Rebuilding an encoded data slice utilizing integrity check values

ABSTRACT

A method includes executing a set of read requests regarding a set of encoded data slices stored in storage units of a storage network, where a data segment is encoded in accordance with a dispersed storage error coding function to produce the set of encoded data slices, and where a decode threshold number of encoded data slices of the set of encoded data slices is needed to rebuild a missing or corrupt encoded data slice of the set of encoded data slices. The method further includes determining, for an encoded data slice, whether an integrity check value substantially matches a known integrity check value. When the integrity check value does not substantially match the known integrity check value, the method further rebuilding the encoded data slice based on the decode threshold number of encoded data slices and storing the rebuilt encoded data slice in the storage units.

CROSS REFERENCE TO RELATED PATENTS

The present U.S. Utility Patent Application claims priority pursuant to35 U.S.C. § 120 as a continuation of U.S. Utility application Ser. No.16/692,190, entitled “REBUILDING AN ENCODED DATA SLICE ASSOCIATED WITHRECONSTRUCTION OF A DATA SEGMENT,” filed Nov. 22, 2019, which is acontinuation of U.S. Utility application Ser. No. 16/151,108, entitled“REBUILDING DATA WHILE READING DATA IN A DISPERSED STORAGE NETWORK,”filed Oct. 3, 2018, issued as U.S. Pat. No. 10,503,598 on Dec. 10, 2019,which is a continuation of U.S. Utility application Ser. No. 15/352,292,entitled “REBUILDING DATA WHILE READING DATA IN A DISPERSED STORAGENETWORK,” filed Nov. 15, 2016, issued as U.S. Pat. No. 10,095,580 onOct. 9, 2018, which is a continuation of U.S. Utility application Ser.No. 14/306,312, entitled “REBUILDING DATA WHILE READING DATA IN ADISPERSED STORAGE NETWORK,” filed Jun. 17, 2014, issued as U.S. Pat. No.9,501,360 on Nov. 22, 2016, which claims priority pursuant to 35 U.S.C.§ 119(e) to U.S. Provisional Patent Application No. 61/841,603, entitled“ACCESSING PERMUTATIONS OF DATA WITHIN A DISPERSED STORAGE NETWORK”,filed Jul. 1, 2013, all of which are hereby incorporated herein byreference in their entirety and made part of the present U.S. UtilityPatent Application for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION Technical Field of the Invention

This invention relates generally to computer networks and moreparticularly to dispersed storage of data and distributed taskprocessing of data.

Description of Related Art

Computing devices are known to communicate data, process data, and/orstore data. Such computing devices range from wireless smart phones,laptops, tablets, personal computers (PC), work stations, and video gamedevices, to data centers that support millions of web searches, stocktrades, or on-line purchases every day. In general, a computing deviceincludes a central processing unit (CPU), a memory system, userinput/output interfaces, peripheral device interfaces, and aninterconnecting bus structure.

As is further known, a computer may effectively extend its CPU by using“cloud computing” to perform one or more computing functions (e.g., aservice, an application, an algorithm, an arithmetic logic function,etc.) on behalf of the computer. Further, for large services,applications, and/or functions, cloud computing may be performed bymultiple cloud computing resources in a distributed manner to improvethe response time for completion of the service, application, and/orfunction. For example, Hadoop is an open source software framework thatsupports distributed applications enabling application execution bythousands of computers.

In addition to cloud computing, a computer may use “cloud storage” aspart of its memory system. As is known, cloud storage enables a user,via its computer, to store files, applications, etc. on an Internetstorage system. The Internet storage system may include a RAID(redundant array of independent disks) system and/or a dispersed storagesystem that uses an error correction scheme to encode data for storage.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic block diagram of an embodiment of a distributedcomputing system in accordance with the present invention;

FIG. 2 is a schematic block diagram of an embodiment of a computing corein accordance with the present invention;

FIG. 3 is a diagram of an example of a distributed storage and taskprocessing in accordance with the present invention;

FIG. 4 is a schematic block diagram of an embodiment of an outbounddistributed storage and/or task (DST) processing in accordance with thepresent invention;

FIG. 5 is a logic diagram of an example of a method for outbound DSTprocessing in accordance with the present invention;

FIG. 6 is a schematic block diagram of an embodiment of a dispersederror encoding in accordance with the present invention;

FIG. 7 is a diagram of an example of a segment processing of thedispersed error encoding in accordance with the present invention;

FIG. 8 is a diagram of an example of error encoding and slicingprocessing of the dispersed error encoding in accordance with thepresent invention;

FIG. 9 is a diagram of an example of grouping selection processing ofthe outbound DST processing in accordance with the present invention;

FIG. 10 is a diagram of an example of converting data into slice groupsin accordance with the present invention;

FIG. 11 is a schematic block diagram of an embodiment of a DST executionunit in accordance with the present invention;

FIG. 12 is a schematic block diagram of an example of operation of a DSTexecution unit in accordance with the present invention;

FIG. 13 is a schematic block diagram of an embodiment of an inbounddistributed storage and/or task (DST) processing in accordance with thepresent invention;

FIG. 14 is a logic diagram of an example of a method for inbound DSTprocessing in accordance with the present invention;

FIG. 15 is a diagram of an example of de-grouping selection processingof the inbound DST processing in accordance with the present invention;

FIG. 16 is a schematic block diagram of an embodiment of a dispersederror decoding in accordance with the present invention;

FIG. 17 is a diagram of an example of de-slicing and error decodingprocessing of the dispersed error decoding in accordance with thepresent invention;

FIG. 18 is a diagram of an example of a de-segment processing of thedispersed error decoding in accordance with the present invention;

FIG. 19 is a diagram of an example of converting slice groups into datain accordance with the present invention;

FIG. 20 is a diagram of an example of a distributed storage within thedistributed computing system in accordance with the present invention;

FIG. 21 is a schematic block diagram of an example of operation ofoutbound distributed storage and/or task (DST) processing for storingdata in accordance with the present invention;

FIG. 22 is a schematic block diagram of an example of a dispersed errorencoding for the example of FIG. 21 in accordance with the presentinvention;

FIG. 23 is a diagram of an example of converting data into pillar slicegroups for storage in accordance with the present invention;

FIG. 24 is a schematic block diagram of an example of a storageoperation of a DST execution unit in accordance with the presentinvention;

FIG. 25 is a schematic block diagram of an example of operation ofinbound distributed storage and/or task (DST) processing for retrievingdispersed error encoded data in accordance with the present invention;

FIG. 26 is a schematic block diagram of an example of a dispersed errordecoding for the example of FIG. 25 in accordance with the presentinvention;

FIG. 27 is a schematic block diagram of an example of a distributedstorage and task processing network (DSTN) module storing a plurality ofdata and a plurality of task codes in accordance with the presentinvention;

FIG. 28 is a schematic block diagram of an example of the distributedcomputing system performing tasks on stored data in accordance with thepresent invention;

FIG. 29 is a schematic block diagram of an embodiment of a taskdistribution module facilitating the example of FIG. 28 in accordancewith the present invention;

FIG. 30 is a diagram of a specific example of the distributed computingsystem performing tasks on stored data in accordance with the presentinvention;

FIG. 31 is a schematic block diagram of an example of a distributedstorage and task processing network (DSTN) module storing data and taskcodes for the example of FIG. 30 in accordance with the presentinvention;

FIG. 32 is a diagram of an example of DST allocation information for theexample of FIG. 30 in accordance with the present invention;

FIGS. 33-38 are schematic block diagrams of the DSTN module performingthe example of FIG. 30 in accordance with the present invention;

FIG. 39 is a diagram of an example of combining result information intofinal results for the example of FIG. 30 in accordance with the presentinvention;

FIG. 40A is a schematic block diagram of an embodiment of a dispersedstorage network in accordance with the present invention;

FIG. 40B is a diagram of an embodiment of a structure of a provenanceobject in accordance with the present invention;

FIG. 40C is a diagram of an embodiment of a set of dispersedhierarchical indexes in accordance with the present invention;

FIG. 40D is a flowchart illustrating an example of generating provenanceinformation in accordance with the present invention;

FIG. 41 is a flowchart illustrating an example of identifying apotential error in accordance with the present invention;

FIG. 42A is a diagram of another embodiment of a dispersed storagenetwork in accordance with the present invention;

FIG. 42B is a flowchart illustrating an example of accessing data inaccordance with the present invention;

FIG. 43A is a diagram of another embodiment of a dispersed storagenetwork in accordance with the present invention;

FIG. 43B is a flowchart illustrating an example of accessing permuteddata in accordance with the present invention;

FIG. 44A is a diagram of another embodiment of a dispersed storagenetwork in accordance with the present invention;

FIG. 44B is a flowchart illustrating another example of accessingpermuted data in accordance with the present invention;

FIGS. 45A-D are diagrams of another embodiment of a dispersed storagenetwork (DSN) illustrating an example of rebuilding data in accordancewith the present invention;

FIG. 45E is a flowchart illustrating an example of rebuilding data inaccordance with the present invention;

FIG. 46A is a diagram of another embodiment of a dispersed storagenetwork in accordance with the present invention; and

FIG. 46B is a flowchart illustrating an example of updatingconfiguration information and software in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram of an embodiment of a distributedcomputing system 10 that includes a user device 12 and/or a user device14, a distributed storage and/or task (DST) processing unit 16, adistributed storage and/or task network (DSTN) managing unit 18, a DSTintegrity processing unit 20, and a distributed storage and/or tasknetwork (DSTN) module 22. The components of the distributed computingsystem 10 are coupled via a network 24, which may include one or morewireless and/or wire lined communication systems; one or more privateintranet systems and/or public internet systems; and/or one or morelocal area networks (LAN) and/or wide area networks (WAN).

The DSTN module 22 includes a plurality of distributed storage and/ortask (DST) execution units 36 that may be located at geographicallydifferent sites (e.g., one in Chicago, one in Milwaukee, etc.). Each ofthe DST execution units is operable to store dispersed error encodeddata and/or to execute, in a distributed manner, one or more tasks ondata. The tasks may be a simple function (e.g., a mathematical function,a logic function, an identify function, a find function, a search enginefunction, a replace function, etc.), a complex function (e.g.,compression, human and/or computer language translation, text-to-voiceconversion, voice-to-text conversion, etc.), multiple simple and/orcomplex functions, one or more algorithms, one or more applications,etc.

Each of the user devices 12-14, the DST processing unit 16, the DSTNmanaging unit 18, and the DST integrity processing unit 20 include acomputing core 26 and may be a portable computing device and/or a fixedcomputing device. A portable computing device may be a social networkingdevice, a gaming device, a cell phone, a smart phone, a personal digitalassistant, a digital music player, a digital video player, a laptopcomputer, a handheld computer, a tablet, a video game controller, and/orany other portable device that includes a computing core. A fixedcomputing device may be a personal computer (PC), a computer server, acable set-top box, a satellite receiver, a television set, a printer, afax machine, home entertainment equipment, a video game console, and/orany type of home or office computing equipment. User device 12 and DSTprocessing unit 16 are configured to include a DST client module 34.

With respect to interfaces, each interface 30, 32, and 33 includessoftware and/or hardware to support one or more communication links viathe network 24 indirectly and/or directly. For example, interface 30supports a communication link (e.g., wired, wireless, direct, via a LAN,via the network 24, etc.) between user device 14 and the DST processingunit 16. As another example, interface 32 supports communication links(e.g., a wired connection, a wireless connection, a LAN connection,and/or any other type of connection to/from the network 24) between userdevice 12 and the DSTN module 22 and between the DST processing unit 16and the DSTN module 22. As yet another example, interface 33 supports acommunication link for each of the DSTN managing unit 18 and DSTintegrity processing unit 20 to the network 24.

The distributed computing system 10 is operable to support dispersedstorage (DS) error encoded data storage and retrieval, to supportdistributed task processing on received data, and/or to supportdistributed task processing on stored data. In general and with respectto DS error encoded data storage and retrieval, the distributedcomputing system 10 supports three primary operations: storagemanagement, data storage and retrieval (an example of which will bediscussed with reference to FIGS. 20-26), and data storage integrityverification. In accordance with these three primary functions, data canbe encoded, distributedly stored in physically different locations, andsubsequently retrieved in a reliable and secure manner. Such a system istolerant of a significant number of failures (e.g., up to a failurelevel, which may be greater than or equal to a pillar width minus adecode threshold minus one) that may result from individual storagedevice failures and/or network equipment failures without loss of dataand without the need for a redundant or backup copy. Further, the systemallows the data to be stored for an indefinite period of time withoutdata loss and does so in a secure manner (e.g., the system is veryresistant to attempts at hacking the data).

The second primary function (i.e., distributed data storage andretrieval) begins and ends with a user device 12-14. For instance, if asecond type of user device 14 has data 40 to store in the DSTN module22, it sends the data 40 to the DST processing unit 16 via its interface30. The interface 30 functions to mimic a conventional operating system(OS) file system interface (e.g., network file system (NFS), flash filesystem (FFS), disk file system (DFS), file transfer protocol (FTP),web-based distributed authoring and versioning (WebDAV), etc.) and/or ablock memory interface (e.g., small computer system interface (SCSI),internet small computer system interface (iSCSI), etc.). In addition,the interface 30 may attach a user identification code (ID) to the data40.

To support storage management, the DSTN managing unit 18 performs DSmanagement services. One such DS management service includes the DSTNmanaging unit 18 establishing distributed data storage parameters (e.g.,vault creation, distributed storage parameters, security parameters,billing information, user profile information, etc.) for a user device12-14 individually or as part of a group of user devices. For example,the DSTN managing unit 18 coordinates creation of a vault (e.g., avirtual memory block) within memory of the DSTN module 22 for a userdevice, a group of devices, or for public access and establishes pervault dispersed storage (DS) error encoding parameters for a vault. TheDSTN managing unit 18 may facilitate storage of DS error encodingparameters for each vault of a plurality of vaults by updating registryinformation for the distributed computing system 10. The facilitatingincludes storing updated registry information in one or more of the DSTNmodule 22, the user device 12, the DST processing unit 16, and the DSTintegrity processing unit 20.

The DS error encoding parameters (e.g., or dispersed storage errorcoding parameters) include data segmenting information (e.g., how manysegments data (e.g., a file, a group of files, a data block, etc.) isdivided into), segment security information (e.g., per segmentencryption, compression, integrity checksum, etc.), error codinginformation (e.g., pillar width, decode threshold, read threshold, writethreshold, etc.), slicing information (e.g., the number of encoded dataslices that will be created for each data segment); and slice securityinformation (e.g., per encoded data slice encryption, compression,integrity checksum, etc.).

The DSTN managing unit 18 creates and stores user profile information(e.g., an access control list (ACL)) in local memory and/or withinmemory of the DSTN module 22. The user profile information includesauthentication information, permissions, and/or the security parameters.The security parameters may include encryption/decryption scheme, one ormore encryption keys, key generation scheme, and/or dataencoding/decoding scheme.

The DSTN managing unit 18 creates billing information for a particularuser, a user group, a vault access, public vault access, etc. Forinstance, the DSTN managing unit 18 tracks the number of times a useraccesses a private vault and/or public vaults, which can be used togenerate a per-access billing information. In another instance, the DSTNmanaging unit 18 tracks the amount of data stored and/or retrieved by auser device and/or a user group, which can be used to generate aper-data-amount billing information.

Another DS management service includes the DSTN managing unit 18performing network operations, network administration, and/or networkmaintenance. Network operations includes authenticating user dataallocation requests (e.g., read and/or write requests), managingcreation of vaults, establishing authentication credentials for userdevices, adding/deleting components (e.g., user devices, DST executionunits, and/or DST processing units) from the distributed computingsystem 10, and/or establishing authentication credentials for DSTexecution units 36. Network administration includes monitoring devicesand/or units for failures, maintaining vault information, determiningdevice and/or unit activation status, determining device and/or unitloading, and/or determining any other system level operation thataffects the performance level of the system 10. Network maintenanceincludes facilitating replacing, upgrading, repairing, and/or expandinga device and/or unit of the system 10.

To support data storage integrity verification within the distributedcomputing system 10, the DST integrity processing unit 20 performsrebuilding of ‘bad’ or missing encoded data slices. At a high level, theDST integrity processing unit 20 performs rebuilding by periodicallyattempting to retrieve/list encoded data slices, and/or slice names ofthe encoded data slices, from the DSTN module 22. For retrieved encodedslices, they are checked for errors due to data corruption, outdatedversion, etc. If a slice includes an error, it is flagged as a ‘bad’slice. For encoded data slices that were not received and/or not listed,they are flagged as missing slices. Bad and/or missing slices aresubsequently rebuilt using other retrieved encoded data slices that aredeemed to be good slices to produce rebuilt slices. The rebuilt slicesare stored in memory of the DSTN module 22. Note that the DST integrityprocessing unit 20 may be a separate unit as shown, it may be includedin the DSTN module 22, it may be included in the DST processing unit 16,and/or distributed among the DST execution units 36.

To support distributed task processing on received data, the distributedcomputing system 10 has two primary operations: DST (distributed storageand/or task processing) management and DST execution on received data(an example of which will be discussed with reference to FIGS. 3-19).With respect to the storage portion of the DST management, the DSTNmanaging unit 18 functions as previously described. With respect to thetasking processing of the DST management, the DSTN managing unit 18performs distributed task processing (DTP) management services. One suchDTP management service includes the DSTN managing unit 18 establishingDTP parameters (e.g., user-vault affiliation information, billinginformation, user-task information, etc.) for a user device 12-14individually or as part of a group of user devices.

Another DTP management service includes the DSTN managing unit 18performing DTP network operations, network administration (which isessentially the same as described above), and/or network maintenance(which is essentially the same as described above). Network operationsinclude, but are not limited to, authenticating user task processingrequests (e.g., valid request, valid user, etc.), authenticating resultsand/or partial results, establishing DTP authentication credentials foruser devices, adding/deleting components (e.g., user devices, DSTexecution units, and/or DST processing units) from the distributedcomputing system, and/or establishing DTP authentication credentials forDST execution units.

To support distributed task processing on stored data, the distributedcomputing system 10 has two primary operations: DST (distributed storageand/or task) management and DST execution on stored data. With respectto the DST execution on stored data, if the second type of user device14 has a task request 38 for execution by the DSTN module 22, it sendsthe task request 38 to the DST processing unit 16 via its interface 30.An example of DST execution on stored data will be discussed in greaterdetail with reference to FIGS. 27-39. With respect to the DSTmanagement, it is substantially similar to the DST management to supportdistributed task processing on received data.

FIG. 2 is a schematic block diagram of an embodiment of a computing core26 that includes a processing module 50, a memory controller 52, mainmemory 54, a video graphics processing unit 55, an input/output (IO)controller 56, a peripheral component interconnect (PCI) interface 58,an IO interface module 60, at least one IO device interface module 62, aread only memory (ROM) basic input output system (BIOS) 64, and one ormore memory interface modules. The one or more memory interfacemodule(s) includes one or more of a universal serial bus (USB) interfacemodule 66, a host bus adapter (HBA) interface module 68, a networkinterface module 70, a flash interface module 72, a hard drive interfacemodule 74, and a DSTN interface module 76.

The DSTN interface module 76 functions to mimic a conventional operatingsystem (OS) file system interface (e.g., network file system (NFS),flash file system (FFS), disk file system (DFS), file transfer protocol(FTP), web-based distributed authoring and versioning (WebDAV), etc.)and/or a block memory interface (e.g., small computer system interface(SCSI), internet small computer system interface (iSCSI), etc.). TheDSTN interface module 76 and/or the network interface module 70 mayfunction as the interface 30 of the user device 14 of FIG. 1. Furthernote that the IO device interface module 62 and/or the memory interfacemodules may be collectively or individually referred to as IO ports.

FIG. 3 is a diagram of an example of the distributed computing systemperforming a distributed storage and task processing operation. Thedistributed computing system includes a DST (distributed storage and/ortask) client module 34 (which may be in user device 14 and/or in DSTprocessing unit 16 of FIG. 1), a network 24, a plurality of DSTexecution units 1-n that includes two or more DST execution units 36 ofFIG. 1 (which form at least a portion of DSTN module 22 of FIG. 1), aDST managing module (not shown), and a DST integrity verification module(not shown). The DST client module 34 includes an outbound DSTprocessing section 80 and an inbound DST processing section 82. Each ofthe DST execution units 1-n includes a controller 86, a processingmodule 84, memory 88, a DT (distributed task) execution module 90, and aDST client module 34.

In an example of operation, the DST client module 34 receives data 92and one or more tasks 94 to be performed upon the data 92. The data 92may be of any size and of any content, where, due to the size (e.g.,greater than a few Terabytes), the content (e.g., secure data, etc.),and/or task(s) (e.g., MIPS intensive), distributed processing of thetask(s) on the data is desired. For example, the data 92 may be one ormore digital books, a copy of a company's emails, a large-scale Internetsearch, a video security file, one or more entertainment video files(e.g., television programs, movies, etc.), data files, and/or any otherlarge amount of data (e.g., greater than a few Terabytes).

Within the DST client module 34, the outbound DST processing section 80receives the data 92 and the task(s) 94. The outbound DST processingsection 80 processes the data 92 to produce slice groupings 96. As anexample of such processing, the outbound DST processing section 80partitions the data 92 into a plurality of data partitions. For eachdata partition, the outbound DST processing section 80 dispersed storage(DS) error encodes the data partition to produce encoded data slices andgroups the encoded data slices into a slice grouping 96. In addition,the outbound DST processing section 80 partitions the task 94 intopartial tasks 98, where the number of partial tasks 98 may correspond tothe number of slice groupings 96.

The outbound DST processing section 80 then sends, via the network 24,the slice groupings 96 and the partial tasks 98 to the DST executionunits 1-n of the DSTN module 22 of FIG. 1. For example, the outbound DSTprocessing section 80 sends slice group 1 and partial task 1 to DSTexecution unit 1. As another example, the outbound DST processingsection 80 sends slice group #n and partial task #n to DST executionunit #n.

Each DST execution unit performs its partial task 98 upon its slicegroup 96 to produce partial results 102. For example, DST execution unit#1 performs partial task #1 on slice group #1 to produce a partialresult #1, for results. As a more specific example, slice group #1corresponds to a data partition of a series of digital books and thepartial task #1 corresponds to searching for specific phrases, recordingwhere the phrase is found, and establishing a phrase count. In this morespecific example, the partial result #1 includes information as to wherethe phrase was found and includes the phrase count.

Upon completion of generating their respective partial results 102, theDST execution units send, via the network 24, their partial results 102to the inbound DST processing section 82 of the DST client module 34.The inbound DST processing section 82 processes the received partialresults 102 to produce a result 104. Continuing with the specificexample of the preceding paragraph, the inbound DST processing section82 combines the phrase count from each of the DST execution units 36 toproduce a total phrase count. In addition, the inbound DST processingsection 82 combines the ‘where the phrase was found’ information fromeach of the DST execution units 36 within their respective datapartitions to produce ‘where the phrase was found’ information for theseries of digital books.

In another example of operation, the DST client module 34 requestsretrieval of stored data within the memory of the DST execution units 36(e.g., memory of the DSTN module). In this example, the task 94 isretrieve data stored in the memory of the DSTN module. Accordingly, theoutbound DST processing section 80 converts the task 94 into a pluralityof partial tasks 98 and sends the partial tasks 98 to the respective DSTexecution units 1-n.

In response to the partial task 98 of retrieving stored data, a DSTexecution unit 36 identifies the corresponding encoded data slices 100and retrieves them. For example, DST execution unit #1 receives partialtask #1 and retrieves, in response thereto, retrieved slices #1. The DSTexecution units 36 send their respective retrieved slices 100 to theinbound DST processing section 82 via the network 24.

The inbound DST processing section 82 converts the retrieved slices 100into data 92. For example, the inbound DST processing section 82de-groups the retrieved slices 100 to produce encoded slices per datapartition. The inbound DST processing section 82 then DS error decodesthe encoded slices per data partition to produce data partitions. Theinbound DST processing section 82 de-partitions the data partitions torecapture the data 92.

FIG. 4 is a schematic block diagram of an embodiment of an outbounddistributed storage and/or task (DST) processing section 80 of a DSTclient module 34 FIG. 1 coupled to a DSTN module 22 of a FIG. 1 (e.g., aplurality of n DST execution units 36) via a network 24. The outboundDST processing section 80 includes a data partitioning module 110, adispersed storage (DS) error encoding module 112, a grouping selectormodule 114, a control module 116, and a distributed task control module118.

In an example of operation, the data partitioning module 110 partitionsdata 92 into a plurality of data partitions 120. The number ofpartitions and the size of the partitions may be selected by the controlmodule 116 via control 160 based on the data 92 (e.g., its size, itscontent, etc.), a corresponding task 94 to be performed (e.g., simple,complex, single step, multiple steps, etc.), DS encoding parameters(e.g., pillar width, decode threshold, write threshold, segment securityparameters, slice security parameters, etc.), capabilities of the DSTexecution units 36 (e.g., processing resources, availability ofprocessing recourses, etc.), and/or as may be inputted by a user, systemadministrator, or other operator (human or automated). For example, thedata partitioning module 110 partitions the data 92 (e.g., 100Terabytes) into 100,000 data segments, each being 1 Gigabyte in size.Alternatively, the data partitioning module 110 partitions the data 92into a plurality of data segments, where some of data segments are of adifferent size, are of the same size, or a combination thereof.

The DS error encoding module 112 receives the data partitions 120 in aserial manner, a parallel manner, and/or a combination thereof. For eachdata partition 120, the DS error encoding module 112 DS error encodesthe data partition 120 in accordance with control information 160 fromthe control module 116 to produce encoded data slices 122. The DS errorencoding includes segmenting the data partition into data segments,segment security processing (e.g., encryption, compression,watermarking, integrity check (e.g., CRC), etc.), error encoding,slicing, and/or per slice security processing (e.g., encryption,compression, watermarking, integrity check (e.g., CRC), etc.). Thecontrol information 160 indicates which steps of the DS error encodingare active for a given data partition and, for active steps, indicatesthe parameters for the step. For example, the control information 160indicates that the error encoding is active and includes error encodingparameters (e.g., pillar width, decode threshold, write threshold, readthreshold, type of error encoding, etc.).

The grouping selector module 114 groups the encoded slices 122 of a datapartition into a set of slice groupings 96. The number of slicegroupings corresponds to the number of DST execution units 36 identifiedfor a particular task 94. For example, if five DST execution units 36are identified for the particular task 94, the grouping selector modulegroups the encoded slices 122 of a data partition into five slicegroupings 96. The grouping selector module 114 outputs the slicegroupings 96 to the corresponding DST execution units 36 via the network24.

The distributed task control module 118 receives the task 94 andconverts the task 94 into a set of partial tasks 98. For example, thedistributed task control module 118 receives a task to find where in thedata (e.g., a series of books) a phrase occurs and a total count of thephrase usage in the data. In this example, the distributed task controlmodule 118 replicates the task 94 for each DST execution unit 36 toproduce the partial tasks 98. In another example, the distributed taskcontrol module 118 receives a task to find where in the data a firstphrase occurs, where in the data a second phrase occurs, and a totalcount for each phrase usage in the data. In this example, thedistributed task control module 118 generates a first set of partialtasks 98 for finding and counting the first phrase and a second set ofpartial tasks for finding and counting the second phrase. Thedistributed task control module 118 sends respective first and/or secondpartial tasks 98 to each DST execution unit 36.

FIG. 5 is a logic diagram of an example of a method for outbounddistributed storage and task (DST) processing that begins at step 126where a DST client module receives data and one or more correspondingtasks. The method continues at step 128 where the DST client moduledetermines a number of DST units to support the task for one or moredata partitions. For example, the DST client module may determine thenumber of DST units to support the task based on the size of the data,the requested task, the content of the data, a predetermined number(e.g., user indicated, system administrator determined, etc.), availableDST units, capability of the DST units, and/or any other factorregarding distributed task processing of the data. The DST client modulemay select the same DST units for each data partition, may selectdifferent DST units for the data partitions, or a combination thereof.

The method continues at step 130 where the DST client module determinesprocessing parameters of the data based on the number of DST unitsselected for distributed task processing. The processing parametersinclude data partitioning information, DS encoding parameters, and/orslice grouping information. The data partitioning information includes anumber of data partitions, size of each data partition, and/ororganization of the data partitions (e.g., number of data blocks in apartition, the size of the data blocks, and arrangement of the datablocks). The DS encoding parameters include segmenting information,segment security information, error encoding information (e.g.,dispersed storage error encoding function parameters including one ormore of pillar width, decode threshold, write threshold, read threshold,generator matrix), slicing information, and/or per slice securityinformation. The slice grouping information includes informationregarding how to arrange the encoded data slices into groups for theselected DST units. As a specific example, if the DST client moduledetermines that five DST units are needed to support the task, then itdetermines that the error encoding parameters include a pillar width offive and a decode threshold of three.

The method continues at step 132 where the DST client module determinestask partitioning information (e.g., how to partition the tasks) basedon the selected DST units and data processing parameters. The dataprocessing parameters include the processing parameters and DST unitcapability information. The DST unit capability information includes thenumber of DT (distributed task) execution units, execution capabilitiesof each DT execution unit (e.g., MIPS capabilities, processing resources(e.g., quantity and capability of microprocessors, CPUs, digital signalprocessors, co-processor, microcontrollers, arithmetic logic circuitry,and/or any other analog and/or digital processing circuitry),availability of the processing resources, memory information (e.g.,type, size, availability, etc.)), and/or any information germane toexecuting one or more tasks.

The method continues at step 134 where the DST client module processesthe data in accordance with the processing parameters to produce slicegroupings. The method continues at step 136 where the DST client modulepartitions the task based on the task partitioning information toproduce a set of partial tasks. The method continues at step 138 wherethe DST client module sends the slice groupings and the correspondingpartial tasks to respective DST units.

FIG. 6 is a schematic block diagram of an embodiment of the dispersedstorage (DS) error encoding module 112 of an outbound distributedstorage and task (DST) processing section. The DS error encoding module112 includes a segment processing module 142, a segment securityprocessing module 144, an error encoding module 146, a slicing module148, and a per slice security processing module 150. Each of thesemodules is coupled to a control module 116 to receive controlinformation 160 therefrom.

In an example of operation, the segment processing module 142 receives adata partition 120 from a data partitioning module and receivessegmenting information as the control information 160 from the controlmodule 116. The segmenting information indicates how the segmentprocessing module 142 is to segment the data partition 120. For example,the segmenting information indicates how many rows to segment the databased on a decode threshold of an error encoding scheme, indicates howmany columns to segment the data into based on a number and size of datablocks within the data partition 120, and indicates how many columns toinclude in a data segment 152. The segment processing module 142segments the data 120 into data segments 152 in accordance with thesegmenting information.

The segment security processing module 144, when enabled by the controlmodule 116, secures the data segments 152 based on segment securityinformation received as control information 160 from the control module116. The segment security information includes data compression,encryption, watermarking, integrity check (e.g., cyclic redundancy check(CRC), etc.), and/or any other type of digital security. For example,when the segment security processing module 144 is enabled, it maycompress a data segment 152, encrypt the compressed data segment, andgenerate a CRC value for the encrypted data segment to produce a securedata segment 154. When the segment security processing module 144 is notenabled, it passes the data segments 152 to the error encoding module146 or is bypassed such that the data segments 152 are provided to theerror encoding module 146.

The error encoding module 146 encodes the secure data segments 154 inaccordance with error correction encoding parameters received as controlinformation 160 from the control module 116. The error correctionencoding parameters (e.g., also referred to as dispersed storage errorcoding parameters) include identifying an error correction encodingscheme (e.g., forward error correction algorithm, a Reed-Solomon basedalgorithm, an online coding algorithm, an information dispersalalgorithm, etc.), a pillar width, a decode threshold, a read threshold,a write threshold, etc. For example, the error correction encodingparameters identify a specific error correction encoding scheme,specifies a pillar width of five, and specifies a decode threshold ofthree. From these parameters, the error encoding module 146 encodes adata segment 154 to produce an encoded data segment 156.

The slicing module 148 slices the encoded data segment 156 in accordancewith the pillar width of the error correction encoding parametersreceived as control information 160. For example, if the pillar width isfive, the slicing module 148 slices an encoded data segment 156 into aset of five encoded data slices. As such, for a plurality of encodeddata segments 156 for a given data partition, the slicing module outputsa plurality of sets of encoded data slices 158.

The per slice security processing module 150, when enabled by thecontrol module 116, secures each encoded data slice 158 based on slicesecurity information received as control information 160 from thecontrol module 116. The slice security information includes datacompression, encryption, watermarking, integrity check (e.g., CRC,etc.), and/or any other type of digital security. For example, when theper slice security processing module 150 is enabled, it compresses anencoded data slice 158, encrypts the compressed encoded data slice, andgenerates a CRC value for the encrypted encoded data slice to produce asecure encoded data slice 122. When the per slice security processingmodule 150 is not enabled, it passes the encoded data slices 158 or isbypassed such that the encoded data slices 158 are the output of the DSerror encoding module 112. Note that the control module 116 may beomitted and each module stores its own parameters.

FIG. 7 is a diagram of an example of a segment processing of a dispersedstorage (DS) error encoding module. In this example, a segmentprocessing module 142 receives a data partition 120 that includes 45data blocks (e.g., d1-d45), receives segmenting information (i.e.,control information 160) from a control module, and segments the datapartition 120 in accordance with the control information 160 to producedata segments 152. Each data block may be of the same size as other datablocks or of a different size. In addition, the size of each data blockmay be a few bytes to megabytes of data. As previously mentioned, thesegmenting information indicates how many rows to segment the datapartition into, indicates how many columns to segment the data partitioninto, and indicates how many columns to include in a data segment.

In this example, the decode threshold of the error encoding scheme isthree; as such the number of rows to divide the data partition into isthree. The number of columns for each row is set to 15, which is basedon the number and size of data blocks. The data blocks of the datapartition are arranged in rows and columns in a sequential order (i.e.,the first row includes the first 15 data blocks; the second row includesthe second 15 data blocks; and the third row includes the last 15 datablocks).

With the data blocks arranged into the desired sequential order, theyare divided into data segments based on the segmenting information. Inthis example, the data partition is divided into 8 data segments; thefirst 7 include 2 columns of three rows and the last includes 1 columnof three rows. Note that the first row of the 8 data segments is insequential order of the first 15 data blocks; the second row of the 8data segments in sequential order of the second 15 data blocks; and thethird row of the 8 data segments in sequential order of the last 15 datablocks. Note that the number of data blocks, the grouping of the datablocks into segments, and size of the data blocks may vary toaccommodate the desired distributed task processing function.

FIG. 8 is a diagram of an example of error encoding and slicingprocessing of the dispersed error encoding processing the data segmentsof FIG. 7. In this example, data segment 1 includes 3 rows with each rowbeing treated as one word for encoding. As such, data segment 1 includesthree words for encoding: word 1 including data blocks d1 and d2, word 2including data blocks d16 and d17, and word 3 including data blocks d31and d32. Each of data segments 2-7 includes three words where each wordincludes two data blocks. Data segment 8 includes three words where eachword includes a single data block (e.g., d15, d30, and d45).

In operation, an error encoding module 146 and a slicing module 148convert each data segment into a set of encoded data slices inaccordance with error correction encoding parameters as controlinformation 160. More specifically, when the error correction encodingparameters indicate a unity matrix Reed-Solomon based encodingalgorithm, 5 pillars, and decode threshold of 3, the first three encodeddata slices of the set of encoded data slices for a data segment aresubstantially similar to the corresponding word of the data segment. Forinstance, when the unity matrix Reed-Solomon based encoding algorithm isapplied to data segment 1, the content of the first encoded data slice(DS1_d1&2) of the first set of encoded data slices (e.g., correspondingto data segment 1) is substantially similar to content of the first word(e.g., d1 & d2); the content of the second encoded data slice(DS1_d16&17) of the first set of encoded data slices is substantiallysimilar to content of the second word (e.g., d16 & d17); and the contentof the third encoded data slice (DS1_d31&32) of the first set of encodeddata slices is substantially similar to content of the third word (e.g.,d31 & d32).

The content of the fourth and fifth encoded data slices (e.g., ES1_1 andES1_2) of the first set of encoded data slices include error correctiondata based on the first-third words of the first data segment. With suchan encoding and slicing scheme, retrieving any three of the five encodeddata slices allows the data segment to be accurately reconstructed.

The encoding and slicing of data segments 2-7 yield sets of encoded dataslices similar to the set of encoded data slices of data segment 1. Forinstance, the content of the first encoded data slice (DS2_d3&4) of thesecond set of encoded data slices (e.g., corresponding to data segment2) is substantially similar to content of the first word (e.g., d3 &d4); the content of the second encoded data slice (DS2_d18&19) of thesecond set of encoded data slices is substantially similar to content ofthe second word (e.g., d18 & d19); and the content of the third encodeddata slice (DS2_d33&34) of the second set of encoded data slices issubstantially similar to content of the third word (e.g., d33 & d34).The content of the fourth and fifth encoded data slices (e.g., ES1_1 andES1_2) of the second set of encoded data slices includes errorcorrection data based on the first-third words of the second datasegment.

FIG. 9 is a diagram of an example of grouping selection processing of anoutbound distributed storage and task (DST) processing in accordancewith group selection information as control information 160 from acontrol module. Encoded slices for data partition 122 are grouped inaccordance with the control information 160 to produce slice groupings96. In this example, a grouping selector module 114 organizes theencoded data slices into five slice groupings (e.g., one for each DSTexecution unit of a distributed storage and task network (DSTN) module).As a specific example, the grouping selector module 114 creates a firstslice grouping for a DST execution unit #1, which includes first encodedslices of each of the sets of encoded slices. As such, the first DSTexecution unit receives encoded data slices corresponding to data blocks1-15 (e.g., encoded data slices of contiguous data).

The grouping selector module 114 also creates a second slice groupingfor a DST execution unit #2, which includes second encoded slices ofeach of the sets of encoded slices. As such, the second DST executionunit receives encoded data slices corresponding to data blocks 16-30.The grouping selector module 114 further creates a third slice groupingfor DST execution unit #3, which includes third encoded slices of eachof the sets of encoded slices. As such, the third DST execution unitreceives encoded data slices corresponding to data blocks 31-45.

The grouping selector module 114 creates a fourth slice grouping for DSTexecution unit #4, which includes fourth encoded slices of each of thesets of encoded slices. As such, the fourth DST execution unit receivesencoded data slices corresponding to first error encoding information(e.g., encoded data slices of error coding (EC) data). The groupingselector module 114 further creates a fifth slice grouping for DSTexecution unit #5, which includes fifth encoded slices of each of thesets of encoded slices. As such, the fifth DST execution unit receivesencoded data slices corresponding to second error encoding information.

FIG. 10 is a diagram of an example of converting data 92 into slicegroups that expands on the preceding figures. As shown, the data 92 ispartitioned in accordance with a partitioning function 164 into aplurality of data partitions (1-x, where x is an integer greater than4). Each data partition (or chunkset of data) is encoded and groupedinto slice groupings as previously discussed by an encoding and groupingfunction 166. For a given data partition, the slice groupings are sentto distributed storage and task (DST) execution units. From datapartition to data partition, the ordering of the slice groupings to theDST execution units may vary.

For example, the slice groupings of data partition #1 is sent to the DSTexecution units such that the first DST execution receives first encodeddata slices of each of the sets of encoded data slices, whichcorresponds to a first continuous data chunk of the first data partition(e.g., refer to FIG. 9), a second DST execution receives second encodeddata slices of each of the sets of encoded data slices, whichcorresponds to a second continuous data chunk of the first datapartition, etc.

For the second data partition, the slice groupings may be sent to theDST execution units in a different order than it was done for the firstdata partition. For instance, the first slice grouping of the seconddata partition (e.g., slice group 2_1) is sent to the second DSTexecution unit; the second slice grouping of the second data partition(e.g., slice group 2_2) is sent to the third DST execution unit; thethird slice grouping of the second data partition (e.g., slice group2_3) is sent to the fourth DST execution unit; the fourth slice groupingof the second data partition (e.g., slice group 2_4, which includesfirst error coding information) is sent to the fifth DST execution unit;and the fifth slice grouping of the second data partition (e.g., slicegroup 2_5, which includes second error coding information) is sent tothe first DST execution unit.

The pattern of sending the slice groupings to the set of DST executionunits may vary in a predicted pattern, a random pattern, and/or acombination thereof from data partition to data partition. In addition,from data partition to data partition, the set of DST execution unitsmay change. For example, for the first data partition, DST executionunits 1-5 may be used; for the second data partition, DST executionunits 6-10 may be used; for the third data partition, DST executionunits 3-7 may be used; etc. As is also shown, the task is divided intopartial tasks that are sent to the DST execution units in conjunctionwith the slice groupings of the data partitions.

FIG. 11 is a schematic block diagram of an embodiment of a DST(distributed storage and/or task) execution unit that includes aninterface 169, a controller 86, memory 88, one or more DT (distributedtask) execution modules 90, and a DST client module 34. The memory 88 isof sufficient size to store a significant number of encoded data slices(e.g., thousands of slices to hundreds-of-millions of slices) and mayinclude one or more hard drives and/or one or more solid-state memorydevices (e.g., flash memory, DRAM, etc.).

In an example of storing a slice group, the DST execution modulereceives a slice grouping 96 (e.g., slice group #1) via interface 169.The slice grouping 96 includes, per partition, encoded data slices ofcontiguous data or encoded data slices of error coding (EC) data. Forslice group #1, the DST execution module receives encoded data slices ofcontiguous data for partitions #1 and #x (and potentially others between3 and x) and receives encoded data slices of EC data for partitions #2and #3 (and potentially others between 3 and x). Examples of encodeddata slices of contiguous data and encoded data slices of error coding(EC) data are discussed with reference to FIG. 9. The memory 88 storesthe encoded data slices of slice groupings 96 in accordance with memorycontrol information 174 it receives from the controller 86.

The controller 86 (e.g., a processing module, a CPU, etc.) generates thememory control information 174 based on a partial task(s) 98 anddistributed computing information (e.g., user information (e.g., userID, distributed computing permissions, data access permission, etc.),vault information (e.g., virtual memory assigned to user, user group,temporary storage for task processing, etc.), task validationinformation, etc.). For example, the controller 86 interprets thepartial task(s) 98 in light of the distributed computing information todetermine whether a requestor is authorized to perform the task 98, isauthorized to access the data, and/or is authorized to perform the taskon this particular data. When the requestor is authorized, thecontroller 86 determines, based on the task 98 and/or another input,whether the encoded data slices of the slice grouping 96 are to betemporarily stored or permanently stored. Based on the foregoing, thecontroller 86 generates the memory control information 174 to write theencoded data slices of the slice grouping 96 into the memory 88 and toindicate whether the slice grouping 96 is permanently stored ortemporarily stored.

With the slice grouping 96 stored in the memory 88, the controller 86facilitates execution of the partial task(s) 98. In an example, thecontroller 86 interprets the partial task 98 in light of thecapabilities of the DT execution module(s) 90. The capabilities includeone or more of MIPS capabilities, processing resources (e.g., quantityand capability of microprocessors, CPUs, digital signal processors,co-processor, microcontrollers, arithmetic logic circuitry, and/or anyother analog and/or digital processing circuitry), availability of theprocessing resources, etc. If the controller 86 determines that the DTexecution module(s) 90 have sufficient capabilities, it generates taskcontrol information 176.

The task control information 176 may be a generic instruction (e.g.,perform the task on the stored slice grouping) or a series ofoperational codes. In the former instance, the DT execution module 90includes a co-processor function specifically configured (fixed orprogrammed) to perform the desired task 98. In the latter instance, theDT execution module 90 includes a general processor topology where thecontroller stores an algorithm corresponding to the particular task 98.In this instance, the controller 86 provides the operational codes(e.g., assembly language, source code of a programming language, objectcode, etc.) of the algorithm to the DT execution module 90 forexecution.

Depending on the nature of the task 98, the DT execution module 90 maygenerate intermediate partial results 102 that are stored in the memory88 or in a cache memory (not shown) within the DT execution module 90.In either case, when the DT execution module 90 completes execution ofthe partial task 98, it outputs one or more partial results 102. Thepartial results 102 may also be stored in memory 88.

If, when the controller 86 is interpreting whether capabilities of theDT execution module(s) 90 can support the partial task 98, thecontroller 86 determines that the DT execution module(s) 90 cannotadequately support the task 98 (e.g., does not have the right resources,does not have sufficient available resources, available resources wouldbe too slow, etc.), it then determines whether the partial task 98should be fully offloaded or partially offloaded.

If the controller 86 determines that the partial task 98 should be fullyoffloaded, it generates DST control information 178 and provides it tothe DST client module 34. The DST control information 178 includes thepartial task 98, memory storage information regarding the slice grouping96, and distribution instructions. The distribution instructionsinstruct the DST client module 34 to divide the partial task 98 intosub-partial tasks 172, to divide the slice grouping 96 into sub-slicegroupings 170, and identify other DST execution units. The DST clientmodule 34 functions in a similar manner as the DST client module 34 ofFIGS. 3-10 to produce the sub-partial tasks 172 and the sub-slicegroupings 170 in accordance with the distribution instructions.

The DST client module 34 receives DST feedback 168 (e.g., sub-partialresults), via the interface 169, from the DST execution units to whichthe task was offloaded. The DST client module 34 provides thesub-partial results to the DST execution unit, which processes thesub-partial results to produce the partial result(s) 102.

If the controller 86 determines that the partial task 98 should bepartially offloaded, it determines what portion of the task 98 and/orslice grouping 96 should be processed locally and what should beoffloaded. For the portion that is being locally processed, thecontroller 86 generates task control information 176 as previouslydiscussed. For the portion that is being offloaded, the controller 86generates DST control information 178 as previously discussed.

When the DST client module 34 receives DST feedback 168 (e.g.,sub-partial results) from the DST executions units to which a portion ofthe task was offloaded, it provides the sub-partial results to the DTexecution module 90. The DT execution module 90 processes thesub-partial results with the sub-partial results it created to producethe partial result(s) 102.

The memory 88 may be further utilized to retrieve one or more of storedslices 100, stored results 104, partial results 102 when the DTexecution module 90 stores partial results 102 and/or results 104 in thememory 88. For example, when the partial task 98 includes a retrievalrequest, the controller 86 outputs the memory control 174 to the memory88 to facilitate retrieval of slices 100 and/or results 104.

FIG. 12 is a schematic block diagram of an example of operation of adistributed storage and task (DST) execution unit storing encoded dataslices and executing a task thereon. To store the encoded data slices ofa partition 1 of slice grouping 1, a controller 86 generates writecommands as memory control information 174 such that the encoded slicesare stored in desired locations (e.g., permanent or temporary) withinmemory 88.

Once the encoded slices are stored, the controller 86 provides taskcontrol information 176 to a distributed task (DT) execution module 90.As a first step of executing the task in accordance with the taskcontrol information 176, the DT execution module 90 retrieves theencoded slices from memory 88. The DT execution module 90 thenreconstructs contiguous data blocks of a data partition. As shown forthis example, reconstructed contiguous data blocks of data partition 1include data blocks 1-15 (e.g., d1-d15).

With the contiguous data blocks reconstructed, the DT execution module90 performs the task on the reconstructed contiguous data blocks. Forexample, the task may be to search the reconstructed contiguous datablocks for a particular word or phrase, identify where in thereconstructed contiguous data blocks the particular word or phraseoccurred, and/or count the occurrences of the particular word or phraseon the reconstructed contiguous data blocks. The DST execution unitcontinues in a similar manner for the encoded data slices of otherpartitions in slice grouping 1. Note that with using the unity matrixerror encoding scheme previously discussed, if the encoded data slicesof contiguous data are uncorrupted, the decoding of them is a relativelystraightforward process of extracting the data.

If, however, an encoded data slice of contiguous data is corrupted (ormissing), it can be rebuilt by accessing other DST execution units thatare storing the other encoded data slices of the set of encoded dataslices of the corrupted encoded data slice. In this instance, the DSTexecution unit having the corrupted encoded data slices retrieves atleast three encoded data slices (of contiguous data and of error codingdata) in the set from the other DST execution units (recall for thisexample, the pillar width is 5 and the decode threshold is 3). The DSTexecution unit decodes the retrieved data slices using the DS errorencoding parameters to recapture the corresponding data segment. The DSTexecution unit then re-encodes the data segment using the DS errorencoding parameters to rebuild the corrupted encoded data slice. Oncethe encoded data slice is rebuilt, the DST execution unit functions aspreviously described.

FIG. 13 is a schematic block diagram of an embodiment of an inbounddistributed storage and/or task (DST) processing section 82 of a DSTclient module coupled to DST execution units of a distributed storageand task network (DSTN) module via a network 24. The inbound DSTprocessing section 82 includes a de-grouping module 180, a DS (dispersedstorage) error decoding module 182, a data de-partitioning module 184, acontrol module 186, and a distributed task control module 188. Note thatthe control module 186 and/or the distributed task control module 188may be separate modules from corresponding ones of outbound DSTprocessing section or may be the same modules.

In an example of operation, the DST execution units have completedexecution of corresponding partial tasks on the corresponding slicegroupings to produce partial results 102. The inbound DST processingsection 82 receives the partial results 102 via the distributed taskcontrol module 188. The inbound DST processing section 82 then processesthe partial results 102 to produce a final result, or results 104. Forexample, if the task was to find a specific word or phrase within data,the partial results 102 indicate where in each of the prescribedportions of the data the corresponding DST execution units found thespecific word or phrase. The distributed task control module 188combines the individual partial results 102 for the correspondingportions of the data into a final result 104 for the data as a whole.

In another example of operation, the inbound DST processing section 82is retrieving stored data from the DST execution units (i.e., the DSTNmodule). In this example, the DST execution units output encoded dataslices 100 corresponding to the data retrieval requests. The de-groupingmodule 180 receives retrieved slices 100 and de-groups them to produceencoded data slices per data partition 122. The DS error decoding module182 decodes, in accordance with DS error encoding parameters, theencoded data slices per data partition 122 to produce data partitions120.

The data de-partitioning module 184 combines the data partitions 120into the data 92. The control module 186 controls the conversion ofretrieved slices 100 into the data 92 using control signals 190 to eachof the modules. For instance, the control module 186 providesde-grouping information to the de-grouping module 180, provides the DSerror encoding parameters to the DS error decoding module 182, andprovides de-partitioning information to the data de-partitioning module184.

FIG. 14 is a logic diagram of an example of a method that is executableby distributed storage and task (DST) client module regarding inboundDST processing. The method begins at step 194 where the DST clientmodule receives partial results. The method continues at step 196 wherethe DST client module retrieves the task corresponding to the partialresults. For example, the partial results include header informationthat identifies the requesting entity, which correlates to the requestedtask.

The method continues at step 198 where the DST client module determinesresult processing information based on the task. For example, if thetask were to identify a particular word or phrase within the data, theresult processing information would indicate to aggregate the partialresults for the corresponding portions of the data to produce the finalresult. As another example, if the task were to count the occurrences ofa particular word or phrase within the data, results of processing theinformation would indicate to add the partial results to produce thefinal results. The method continues at step 200 where the DST clientmodule processes the partial results in accordance with the resultprocessing information to produce the final result or results.

FIG. 15 is a diagram of an example of de-grouping selection processingof an inbound distributed storage and task (DST) processing section of aDST client module. In general, this is an inverse process of thegrouping module of the outbound DST processing section of FIG. 9.Accordingly, for each data partition (e.g., partition #1), thede-grouping module retrieves the corresponding slice grouping from theDST execution units (EU) (e.g., DST 1-5).

As shown, DST execution unit #1 provides a first slice grouping, whichincludes the first encoded slices of each of the sets of encoded slices(e.g., encoded data slices of contiguous data of data blocks 1-15); DSTexecution unit #2 provides a second slice grouping, which includes thesecond encoded slices of each of the sets of encoded slices (e.g.,encoded data slices of contiguous data of data blocks 16-30); DSTexecution unit #3 provides a third slice grouping, which includes thethird encoded slices of each of the sets of encoded slices (e.g.,encoded data slices of contiguous data of data blocks 31-45); DSTexecution unit #4 provides a fourth slice grouping, which includes thefourth encoded slices of each of the sets of encoded slices (e.g., firstencoded data slices of error coding (EC) data); and DST execution unit#5 provides a fifth slice grouping, which includes the fifth encodedslices of each of the sets of encoded slices (e.g., first encoded dataslices of error coding (EC) data).

The de-grouping module de-groups the slice groupings (e.g., receivedslices 100) using a de-grouping selector 180 controlled by a controlsignal 190 as shown in the example to produce a plurality of sets ofencoded data slices (e.g., retrieved slices for a partition into sets ofslices 122). Each set corresponding to a data segment of the datapartition.

FIG. 16 is a schematic block diagram of an embodiment of a dispersedstorage (DS) error decoding module 182 of an inbound distributed storageand task (DST) processing section. The DS error decoding module 182includes an inverse per slice security processing module 202, ade-slicing module 204, an error decoding module 206, an inverse segmentsecurity module 208, a de-segmenting processing module 210, and acontrol module 186.

In an example of operation, the inverse per slice security processingmodule 202, when enabled by the control module 186, unsecures eachencoded data slice 122 based on slice de-security information receivedas control information 190 (e.g., the compliment of the slice securityinformation discussed with reference to FIG. 6) received from thecontrol module 186. The slice security information includes datadecompression, decryption, de-watermarking, integrity check (e.g., CRCverification, etc.), and/or any other type of digital security. Forexample, when the inverse per slice security processing module 202 isenabled, it verifies integrity information (e.g., a CRC value) of eachencoded data slice 122, it decrypts each verified encoded data slice,and decompresses each decrypted encoded data slice to produce sliceencoded data 158. When the inverse per slice security processing module202 is not enabled, it passes the encoded data slices 122 as the slicedencoded data 158 or is bypassed such that the retrieved encoded dataslices 122 are provided as the sliced encoded data 158.

The de-slicing module 204 de-slices the sliced encoded data 158 intoencoded data segments 156 in accordance with a pillar width of the errorcorrection encoding parameters received as control information 190 fromthe control module 186. For example, if the pillar width is five, thede-slicing module 204 de-slices a set of five encoded data slices intoan encoded data segment 156. The error decoding module 206 decodes theencoded data segments 156 in accordance with error correction decodingparameters received as control information 190 from the control module186 to produce secure data segments 154. The error correction decodingparameters include identifying an error correction encoding scheme(e.g., forward error correction algorithm, a Reed-Solomon basedalgorithm, an information dispersal algorithm, etc.), a pillar width, adecode threshold, a read threshold, a write threshold, etc. For example,the error correction decoding parameters identify a specific errorcorrection encoding scheme, specify a pillar width of five, and specifya decode threshold of three.

The inverse segment security processing module 208, when enabled by thecontrol module 186, unsecures the secured data segments 154 based onsegment security information received as control information 190 fromthe control module 186. The segment security information includes datadecompression, decryption, de-watermarking, integrity check (e.g., CRC,etc.) verification, and/or any other type of digital security. Forexample, when the inverse segment security processing module 208 isenabled, it verifies integrity information (e.g., a CRC value) of eachsecure data segment 154, it decrypts each verified secured data segment,and decompresses each decrypted secure data segment to produce a datasegment 152. When the inverse segment security processing module 208 isnot enabled, it passes the decoded data segment 154 as the data segment152 or is bypassed.

The de-segment processing module 210 receives the data segments 152 andreceives de-segmenting information as control information 190 from thecontrol module 186. The de-segmenting information indicates how thede-segment processing module 210 is to de-segment the data segments 152into a data partition 120. For example, the de-segmenting informationindicates how the rows and columns of data segments are to be rearrangedto yield the data partition 120.

FIG. 17 is a diagram of an example of de-slicing and error decodingprocessing of a dispersed error decoding module. A de-slicing module 204receives at least a decode threshold number of encoded data slices 158for each data segment in accordance with control information 190 andprovides encoded data 156. In this example, a decode threshold is three.As such, each set of encoded data slices 158 is shown to have threeencoded data slices per data segment. The de-slicing module 204 mayreceive three encoded data slices per data segment because an associateddistributed storage and task (DST) client module requested retrievingonly three encoded data slices per segment or selected three of theretrieved encoded data slices per data segment. As shown, which is basedon the unity matrix encoding previously discussed with reference to FIG.8, an encoded data slice may be a data-based encoded data slice (e.g.,DS1_d1&d2) or an error code based encoded data slice (e.g., ES3_1).

An error decoding module 206 decodes the encoded data 156 of each datasegment in accordance with the error correction decoding parameters ofcontrol information 190 to produce secured segments 154. In thisexample, data segment 1 includes 3 rows with each row being treated asone word for encoding. As such, data segment 1 includes three words:word 1 including data blocks d1 and d2, word 2 including data blocks d16and d17, and word 3 including data blocks d31 and d32. Each of datasegments 2-7 includes three words where each word includes two datablocks. Data segment 8 includes three words where each word includes asingle data block (e.g., d15, d30, and d45).

FIG. 18 is a diagram of an example of a de-segment processing of aninbound distributed storage and task (DST) processing. In this example,a de-segment processing module 210 receives data segments 152 (e.g.,1-8) and rearranges the data blocks of the data segments into rows andcolumns in accordance with de-segmenting information of controlinformation 190 to produce a data partition 120. Note that the number ofrows is based on the decode threshold (e.g., 3 in this specific example)and the number of columns is based on the number and size of the datablocks.

The de-segmenting module 210 converts the rows and columns of datablocks into the data partition 120. Note that each data block may be ofthe same size as other data blocks or of a different size. In addition,the size of each data block may be a few bytes to megabytes of data.

FIG. 19 is a diagram of an example of converting slice groups into data92 within an inbound distributed storage and task (DST) processingsection. As shown, the data 92 is reconstructed from a plurality of datapartitions (1-x, where x is an integer greater than 4). Each datapartition (or chunk set of data) is decoded and re-grouped using ade-grouping and decoding function 212 and a de-partition function 214from slice groupings as previously discussed. For a given datapartition, the slice groupings (e.g., at least a decode threshold perdata segment of encoded data slices) are received from DST executionunits. From data partition to data partition, the ordering of the slicegroupings received from the DST execution units may vary as discussedwith reference to FIG. 10.

FIG. 20 is a diagram of an example of a distributed storage and/orretrieval within the distributed computing system. The distributedcomputing system includes a plurality of distributed storage and/or task(DST) processing client modules 34 (one shown) coupled to a distributedstorage and/or task processing network (DSTN) module, or multiple DSTNmodules, via a network 24. The DST client module 34 includes an outboundDST processing section 80 and an inbound DST processing section 82. TheDSTN module includes a plurality of DST execution units. Each DSTexecution unit includes a controller 86, memory 88, one or moredistributed task (DT) execution modules 90, and a DST client module 34.

In an example of data storage, the DST client module 34 has data 92 thatit desires to store in the DSTN module. The data 92 may be a file (e.g.,video, audio, text, graphics, etc.), a data object, a data block, anupdate to a file, an update to a data block, etc. In this instance, theoutbound DST processing module 80 converts the data 92 into encoded dataslices 216 as will be further described with reference to FIGS. 21-23.The outbound DST processing module 80 sends, via the network 24, to theDST execution units for storage as further described with reference toFIG. 24.

In an example of data retrieval, the DST client module 34 issues aretrieve request to the DST execution units for the desired data 92. Theretrieve request may address each DST executions units storing encodeddata slices of the desired data, address a decode threshold number ofDST execution units, address a read threshold number of DST executionunits, or address some other number of DST execution units. In responseto the request, each addressed DST execution unit retrieves its encodeddata slices 100 of the desired data and sends them to the inbound DSTprocessing section 82, via the network 24.

When, for each data segment, the inbound DST processing section 82receives at least a decode threshold number of encoded data slices 100,it converts the encoded data slices 100 into a data segment. The inboundDST processing section 82 aggregates the data segments to produce theretrieved data 92.

FIG. 21 is a schematic block diagram of an embodiment of an outbounddistributed storage and/or task (DST) processing section 80 of a DSTclient module coupled to a distributed storage and task network (DSTN)module (e.g., a plurality of DST execution units) via a network 24. Theoutbound DST processing section 80 includes a data partitioning module110, a dispersed storage (DS) error encoding module 112, a groupingselector module 114, a control module 116, and a distributed taskcontrol module 118.

In an example of operation, the data partitioning module 110 isby-passed such that data 92 is provided directly to the DS errorencoding module 112. The control module 116 coordinates the by-passingof the data partitioning module 110 by outputting a bypass 220 messageto the data partitioning module 110.

The DS error encoding module 112 receives the data 92 in a serialmanner, a parallel manner, and/or a combination thereof. The DS errorencoding module 112 DS error encodes the data in accordance with controlinformation 160 from the control module 116 to produce encoded dataslices 218. The DS error encoding includes segmenting the data 92 intodata segments, segment security processing (e.g., encryption,compression, watermarking, integrity check (e.g., CRC, etc.)), errorencoding, slicing, and/or per slice security processing (e.g.,encryption, compression, watermarking, integrity check (e.g., CRC,etc.)). The control information 160 indicates which steps of the DSerror encoding are active for the data 92 and, for active steps,indicates the parameters for the step. For example, the controlinformation 160 indicates that the error encoding is active and includeserror encoding parameters (e.g., pillar width, decode threshold, writethreshold, read threshold, type of error encoding, etc.).

The grouping selector module 114 groups the encoded slices 218 of thedata segments into pillars of slices 216. The number of pillarscorresponds to the pillar width of the DS error encoding parameters. Inthis example, the distributed task control module 118 facilitates thestorage request.

FIG. 22 is a schematic block diagram of an example of a dispersedstorage (DS) error encoding module 112 for the example of FIG. 21. TheDS error encoding module 112 includes a segment processing module 142, asegment security processing module 144, an error encoding module 146, aslicing module 148, and a per slice security processing module 150. Eachof these modules is coupled to a control module 116 to receive controlinformation 160 therefrom.

In an example of operation, the segment processing module 142 receivesdata 92 and receives segmenting information as control information 160from the control module 116. The segmenting information indicates howthe segment processing module is to segment the data. For example, thesegmenting information indicates the size of each data segment. Thesegment processing module 142 segments the data 92 into data segments152 in accordance with the segmenting information.

The segment security processing module 144, when enabled by the controlmodule 116, secures the data segments 152 based on segment securityinformation received as control information 160 from the control module116. The segment security information includes data compression,encryption, watermarking, integrity check (e.g., CRC, etc.), and/or anyother type of digital security. For example, when the segment securityprocessing module 144 is enabled, it compresses a data segment 152,encrypts the compressed data segment, and generates a CRC value for theencrypted data segment to produce a secure data segment. When thesegment security processing module 144 is not enabled, it passes thedata segments 152 to the error encoding module 146 or is bypassed suchthat the data segments 152 are provided to the error encoding module146.

The error encoding module 146 encodes the secure data segments inaccordance with error correction encoding parameters received as controlinformation 160 from the control module 116. The error correctionencoding parameters include identifying an error correction encodingscheme (e.g., forward error correction algorithm, a Reed-Solomon basedalgorithm, an information dispersal algorithm, etc.), a pillar width, adecode threshold, a read threshold, a write threshold, etc. For example,the error correction encoding parameters identify a specific errorcorrection encoding scheme, specifies a pillar width of five, andspecifies a decode threshold of three. From these parameters, the errorencoding module 146 encodes a data segment to produce an encoded datasegment.

The slicing module 148 slices the encoded data segment in accordancewith a pillar width of the error correction encoding parameters. Forexample, if the pillar width is five, the slicing module slices anencoded data segment into a set of five encoded data slices. As such,for a plurality of data segments, the slicing module 148 outputs aplurality of sets of encoded data slices as shown within encoding andslicing function 222 as described.

The per slice security processing module 150, when enabled by thecontrol module 116, secures each encoded data slice based on slicesecurity information received as control information 160 from thecontrol module 116. The slice security information includes datacompression, encryption, watermarking, integrity check (e.g., CRC,etc.), and/or any other type of digital security. For example, when theper slice security processing module 150 is enabled, it may compress anencoded data slice, encrypt the compressed encoded data slice, andgenerate a CRC value for the encrypted encoded data slice to produce asecure encoded data slice tweaking. When the per slice securityprocessing module 150 is not enabled, it passes the encoded data slicesor is bypassed such that the encoded data slices 218 are the output ofthe DS error encoding module 112.

FIG. 23 is a diagram of an example of converting data 92 into pillarslice groups utilizing encoding, slicing and pillar grouping function224 for storage in memory of a distributed storage and task network(DSTN) module. As previously discussed the data 92 is encoded and slicedinto a plurality of sets of encoded data slices; one set per datasegment. The grouping selector module organizes the sets of encoded dataslices into pillars of data slices. In this example, the DS errorencoding parameters include a pillar width of 5 and a decode thresholdof 3. As such, for each data segment, 5 encoded data slices are created.

The grouping selector module takes the first encoded data slice of eachof the sets and forms a first pillar, which may be sent to the first DSTexecution unit. Similarly, the grouping selector module creates thesecond pillar from the second slices of the sets; the third pillar fromthe third slices of the sets; the fourth pillar from the fourth slicesof the sets; and the fifth pillar from the fifth slices of the set.

FIG. 24 is a schematic block diagram of an embodiment of a distributedstorage and/or task (DST) execution unit that includes an interface 169,a controller 86, memory 88, one or more distributed task (DT) executionmodules 90, and a DST client module 34. A computing core 26 may beutilized to implement the one or more DT execution modules 90 and theDST client module 34. The memory 88 is of sufficient size to store asignificant number of encoded data slices (e.g., thousands of slices tohundreds-of-millions of slices) and may include one or more hard drivesand/or one or more solid-state memory devices (e.g., flash memory, DRAM,etc.).

In an example of storing a pillar of slices 216, the DST execution unitreceives, via interface 169, a pillar of slices 216 (e.g., pillar #1slices). The memory 88 stores the encoded data slices 216 of the pillarof slices in accordance with memory control information 174 it receivesfrom the controller 86. The controller 86 (e.g., a processing module, aCPU, etc.) generates the memory control information 174 based ondistributed storage information (e.g., user information (e.g., user ID,distributed storage permissions, data access permission, etc.), vaultinformation (e.g., virtual memory assigned to user, user group, etc.),etc.). Similarly, when retrieving slices, the DST execution unitreceives, via interface 169, a slice retrieval request. The memory 88retrieves the slice in accordance with memory control information 174 itreceives from the controller 86. The memory 88 outputs the slice 100,via the interface 169, to a requesting entity.

FIG. 25 is a schematic block diagram of an example of operation of aninbound distributed storage and/or task (DST) processing section 82 forretrieving dispersed error encoded data 92. The inbound DST processingsection 82 includes a de-grouping module 180, a dispersed storage (DS)error decoding module 182, a data de-partitioning module 184, a controlmodule 186, and a distributed task control module 188. Note that thecontrol module 186 and/or the distributed task control module 188 may beseparate modules from corresponding ones of an outbound DST processingsection or may be the same modules.

In an example of operation, the inbound DST processing section 82 isretrieving stored data 92 from the DST execution units (i.e., the DSTNmodule). In this example, the DST execution units output encoded dataslices corresponding to data retrieval requests from the distributedtask control module 188. The de-grouping module 180 receives pillars ofslices 100 and de-groups them in accordance with control information 190from the control module 186 to produce sets of encoded data slices 218.The DS error decoding module 182 decodes, in accordance with the DSerror encoding parameters received as control information 190 from thecontrol module 186, each set of encoded data slices 218 to produce datasegments, which are aggregated into retrieved data 92. The datade-partitioning module 184 is by-passed in this operational mode via abypass signal 226 of control information 190 from the control module186.

FIG. 26 is a schematic block diagram of an embodiment of a dispersedstorage (DS) error decoding module 182 of an inbound distributed storageand task (DST) processing section. The DS error decoding module 182includes an inverse per slice security processing module 202, ade-slicing module 204, an error decoding module 206, an inverse segmentsecurity module 208, and a de-segmenting processing module 210. Thedispersed error decoding module 182 is operable to de-slice and decodeencoded slices per data segment 218 utilizing a de-slicing and decodingfunction 228 to produce a plurality of data segments that arede-segmented utilizing a de-segment function 230 to recover data 92.

In an example of operation, the inverse per slice security processingmodule 202, when enabled by the control module 186 via controlinformation 190, unsecures each encoded data slice 218 based on slicede-security information (e.g., the compliment of the slice securityinformation discussed with reference to FIG. 6) received as controlinformation 190 from the control module 186. The slice de-securityinformation includes data decompression, decryption, de-watermarking,integrity check (e.g., CRC verification, etc.), and/or any other type ofdigital security. For example, when the inverse per slice securityprocessing module 202 is enabled, it verifies integrity information(e.g., a CRC value) of each encoded data slice 218, it decrypts eachverified encoded data slice, and decompresses each decrypted encodeddata slice to produce slice encoded data. When the inverse per slicesecurity processing module 202 is not enabled, it passes the encodeddata slices 218 as the sliced encoded data or is bypassed such that theretrieved encoded data slices 218 are provided as the sliced encodeddata.

The de-slicing module 204 de-slices the sliced encoded data into encodeddata segments in accordance with a pillar width of the error correctionencoding parameters received as control information 190 from a controlmodule 186. For example, if the pillar width is five, the de-slicingmodule de-slices a set of five encoded data slices into an encoded datasegment. Alternatively, the encoded data segment may include just threeencoded data slices (e.g., when the decode threshold is 3).

The error decoding module 206 decodes the encoded data segments inaccordance with error correction decoding parameters received as controlinformation 190 from the control module 186 to produce secure datasegments. The error correction decoding parameters include identifyingan error correction encoding scheme (e.g., forward error correctionalgorithm, a Reed-Solomon based algorithm, an information dispersalalgorithm, etc.), a pillar width, a decode threshold, a read threshold,a write threshold, etc. For example, the error correction decodingparameters identify a specific error correction encoding scheme, specifya pillar width of five, and specify a decode threshold of three.

The inverse segment security processing module 208, when enabled by thecontrol module 186, unsecures the secured data segments based on segmentsecurity information received as control information 190 from thecontrol module 186. The segment security information includes datadecompression, decryption, de-watermarking, integrity check (e.g., CRC,etc.) verification, and/or any other type of digital security. Forexample, when the inverse segment security processing module is enabled,it verifies integrity information (e.g., a CRC value) of each securedata segment, it decrypts each verified secured data segment, anddecompresses each decrypted secure data segment to produce a datasegment 152. When the inverse segment security processing module 208 isnot enabled, it passes the decoded data segment 152 as the data segmentor is bypassed. The de-segmenting processing module 210 aggregates thedata segments 152 into the data 92 in accordance with controlinformation 190 from the control module 186.

FIG. 27 is a schematic block diagram of an example of a distributedstorage and task processing network (DSTN) module that includes aplurality of distributed storage and task (DST) execution units (#1through #n, where, for example, n is an integer greater than or equal tothree). Each of the DST execution units includes a DST client module 34,a controller 86, one or more DT (distributed task) execution modules 90,and memory 88.

In this example, the DSTN module stores, in the memory of the DSTexecution units, a plurality of DS (dispersed storage) encoded data(e.g., 1 through n, where n is an integer greater than or equal to two)and stores a plurality of DS encoded task codes (e.g., 1 through k,where k is an integer greater than or equal to two). The DS encoded datamay be encoded in accordance with one or more examples described withreference to FIGS. 3-19 (e.g., organized in slice groupings) or encodedin accordance with one or more examples described with reference toFIGS. 20-26 (e.g., organized in pillar groups). The data that is encodedinto the DS encoded data may be of any size and/or of any content. Forexample, the data may be one or more digital books, a copy of acompany's emails, a large-scale Internet search, a video security file,one or more entertainment video files (e.g., television programs,movies, etc.), data files, and/or any other large amount of data (e.g.,greater than a few Terabytes).

The tasks that are encoded into the DS encoded task code may be a simplefunction (e.g., a mathematical function, a logic function, an identifyfunction, a find function, a search engine function, a replace function,etc.), a complex function (e.g., compression, human and/or computerlanguage translation, text-to-voice conversion, voice-to-textconversion, etc.), multiple simple and/or complex functions, one or morealgorithms, one or more applications, etc. The tasks may be encoded intothe DS encoded task code in accordance with one or more examplesdescribed with reference to FIGS. 3-19 (e.g., organized in slicegroupings) or encoded in accordance with one or more examples describedwith reference to FIGS. 20-26 (e.g., organized in pillar groups).

In an example of operation, a DST client module of a user device or of aDST processing unit issues a DST request to the DSTN module. The DSTrequest may include a request to retrieve stored data, or a portionthereof, may include a request to store data that is included with theDST request, may include a request to perform one or more tasks onstored data, may include a request to perform one or more tasks on dataincluded with the DST request, etc. In the cases where the DST requestincludes a request to store data or to retrieve data, the client moduleand/or the DSTN module processes the request as previously discussedwith reference to one or more of FIGS. 3-19 (e.g., slice groupings)and/or 20-26 (e.g., pillar groupings). In the case where the DST requestincludes a request to perform one or more tasks on data included withthe DST request, the DST client module and/or the DSTN module processthe DST request as previously discussed with reference to one or more ofFIGS. 3-19.

In the case where the DST request includes a request to perform one ormore tasks on stored data, the DST client module and/or the DSTN moduleprocesses the DST request as will be described with reference to one ormore of FIGS. 28-39. In general, the DST client module identifies dataand one or more tasks for the DSTN module to execute upon the identifieddata. The DST request may be for a one-time execution of the task or foran on-going execution of the task. As an example of the latter, as acompany generates daily emails, the DST request may be to daily searchnew emails for inappropriate content and, if found, record the content,the email sender(s), the email recipient(s), email routing information,notify human resources of the identified email, etc.

FIG. 28 is a schematic block diagram of an example of a distributedcomputing system performing tasks on stored data. In this example, twodistributed storage and task (DST) client modules 1-2 are shown: thefirst may be associated with a user device and the second may beassociated with a DST processing unit or a high priority user device(e.g., high priority clearance user, system administrator, etc.). EachDST client module includes a list of stored data 234 and a list of taskscodes 236. The list of stored data 234 includes one or more entries ofdata identifying information, where each entry identifies data stored inthe DSTN module 22. The data identifying information (e.g., data ID)includes one or more of a data file name, a data file directory listing,DSTN addressing information of the data, a data object identifier, etc.The list of tasks 236 includes one or more entries of task codeidentifying information, when each entry identifies task codes stored inthe DSTN module 22. The task code identifying information (e.g., taskID) includes one or more of a task file name, a task file directorylisting, DSTN addressing information of the task, another type ofidentifier to identify the task, etc.

As shown, the list of data 234 and the list of tasks 236 are eachsmaller in number of entries for the first DST client module than thecorresponding lists of the second DST client module. This may occurbecause the user device associated with the first DST client module hasfewer privileges in the distributed computing system than the deviceassociated with the second DST client module. Alternatively, this mayoccur because the user device associated with the first DST clientmodule serves fewer users than the device associated with the second DSTclient module and is restricted by the distributed computing systemaccordingly. As yet another alternative, this may occur through norestraints by the distributed computing system, it just occurred becausethe operator of the user device associated with the first DST clientmodule has selected fewer data and/or fewer tasks than the operator ofthe device associated with the second DST client module.

In an example of operation, the first DST client module selects one ormore data entries 238 and one or more tasks 240 from its respectivelists (e.g., selected data ID and selected task ID). The first DSTclient module sends its selections to a task distribution module 232.The task distribution module 232 may be within a stand-alone device ofthe distributed computing system, may be within the user device thatcontains the first DST client module, or may be within the DSTN module22.

Regardless of the task distribution module's location, it generates DSTallocation information 242 from the selected task ID 240 and theselected data ID 238. The DST allocation information 242 includes datapartitioning information, task execution information, and/orintermediate result information. The task distribution module 232 sendsthe DST allocation information 242 to the DSTN module 22. Note that oneor more examples of the DST allocation information will be discussedwith reference to one or more of FIGS. 29-39.

The DSTN module 22 interprets the DST allocation information 242 toidentify the stored DS encoded data (e.g., DS error encoded data 2) andto identify the stored DS error encoded task code (e.g., DS errorencoded task code 1). In addition, the DSTN module 22 interprets the DSTallocation information 242 to determine how the data is to bepartitioned and how the task is to be partitioned. The DSTN module 22also determines whether the selected DS error encoded data 238 needs tobe converted from pillar grouping to slice grouping. If so, the DSTNmodule 22 converts the selected DS error encoded data into slicegroupings and stores the slice grouping DS error encoded data byoverwriting the pillar grouping DS error encoded data or by storing itin a different location in the memory of the DSTN module 22 (i.e., doesnot overwrite the pillar grouping DS encoded data).

The DSTN module 22 partitions the data and the task as indicated in theDST allocation information 242 and sends the portions to selected DSTexecution units of the DSTN module 22. Each of the selected DSTexecution units performs its partial task(s) on its slice groupings toproduce partial results. The DSTN module 22 collects the partial resultsfrom the selected DST execution units and provides them, as resultinformation 244, to the task distribution module. The result information244 may be the collected partial results, one or more final results asproduced by the DSTN module 22 from processing the partial results inaccordance with the DST allocation information 242, or one or moreintermediate results as produced by the DSTN module 22 from processingthe partial results in accordance with the DST allocation information242.

The task distribution module 232 receives the result information 244 andprovides one or more final results 104 therefrom to the first DST clientmodule. The final result(s) 104 may be result information 244 or aresult(s) of the task distribution module's processing of the resultinformation 244.

In concurrence with processing the selected task of the first DST clientmodule, the distributed computing system may process the selectedtask(s) of the second DST client module on the selected data(s) of thesecond DST client module. Alternatively, the distributed computingsystem may process the second DST client module's request subsequent to,or preceding, that of the first DST client module. Regardless of theordering and/or parallel processing of the DST client module requests,the second DST client module provides its selected data 238 and selectedtask 240 to a task distribution module 232. If the task distributionmodule 232 is a separate device of the distributed computing system orwithin the DSTN module, the task distribution modules 232 coupled to thefirst and second DST client modules may be the same module. The taskdistribution module 232 processes the request of the second DST clientmodule in a similar manner as it processed the request of the first DSTclient module.

FIG. 29 is a schematic block diagram of an embodiment of a taskdistribution module 232 facilitating the example of FIG. 28. The taskdistribution module 232 includes a plurality of tables it uses togenerate distributed storage and task (DST) allocation information 242for selected data and selected tasks received from a DST client module.The tables include data storage information 248, task storageinformation 250, distributed task (DT) execution module information 252,and task ⇔ sub-task mapping information 246.

The data storage information table 248 includes a data identification(ID) field 260, a data size field 262, an addressing information field264, distributed storage (DS) information 266, and may further includeother information regarding the data, how it is stored, and/or how itcan be processed. For example, DS encoded data #1 has a data ID of 1, adata size of AA (e.g., a byte size of a few Terabytes or more),addressing information of Addr_1_AA, and DS parameters of 3/5; SEG_1;and SLC_1. In this example, the addressing information may be a virtualaddress corresponding to the virtual address of the first storage word(e.g., one or more bytes) of the data and information on how tocalculate the other addresses, may be a range of virtual addresses forthe storage words of the data, physical addresses of the first storageword or the storage words of the data, may be a list of slice names ofthe encoded data slices of the data, etc. The DS parameters may includeidentity of an error encoding scheme, decode threshold/pillar width(e.g., 3/5 for the first data entry), segment security information(e.g., SEG_1), per slice security information (e.g., SLC_1), and/or anyother information regarding how the data was encoded into data slices.

The task storage information table 250 includes a task identification(ID) field 268, a task size field 270, an addressing information field272, distributed storage (DS) information 274, and may further includeother information regarding the task, how it is stored, and/or how itcan be used to process data. For example, DS encoded task #2 has a taskID of 2, a task size of XY, addressing information of Addr_2_XY, and DSparameters of 3/5; SEG_2; and SLC_2. In this example, the addressinginformation may be a virtual address corresponding to the virtualaddress of the first storage word (e.g., one or more bytes) of the taskand information on how to calculate the other addresses, may be a rangeof virtual addresses for the storage words of the task, physicaladdresses of the first storage word or the storage words of the task,may be a list of slices names of the encoded slices of the task code,etc. The DS parameters may include identity of an error encoding scheme,decode threshold/pillar width (e.g., 3/5 for the first data entry),segment security information (e.g., SEG_2), per slice securityinformation (e.g., SLC_2), and/or any other information regarding howthe task was encoded into encoded task slices. Note that the segmentand/or the per-slice security information include a type of encryption(if enabled), a type of compression (if enabled), watermarkinginformation (if enabled), and/or an integrity check scheme (if enabled).

The task ⇔ sub-task mapping information table 246 includes a task field256 and a sub-task field 258. The task field 256 identifies a taskstored in the memory of a distributed storage and task network (DSTN)module and the corresponding sub-task fields 258 indicates whether thetask includes sub-tasks and, if so, how many and if any of the sub-tasksare ordered. In this example, the task ⇔ sub-task mapping informationtable 246 includes an entry for each task stored in memory of the DSTNmodule (e.g., task 1 through task k). In particular, this exampleindicates that task 1 includes 7 sub-tasks; task 2 does not includesub-tasks, and task k includes r number of sub-tasks (where r is aninteger greater than or equal to two).

The DT execution module table 252 includes a DST execution unit ID field276, a DT execution module ID field 278, and a DT execution modulecapabilities field 280. The DST execution unit ID field 276 includes theidentity of DST units in the DSTN module. The DT execution module IDfield 278 includes the identity of each DT execution unit in each DSTunit. For example, DST unit 1 includes three DT executions modules(e.g., 1_1, 1_2, and 1_3). The DT execution capabilities field 280includes identity of the capabilities of the corresponding DT executionunit. For example, DT execution module 1_1 includes capabilities X,where X includes one or more of MIPS capabilities, processing resources(e.g., quantity and capability of microprocessors, CPUs, digital signalprocessors, co-processor, microcontrollers, arithmetic logic circuitry,and/or any other analog and/or digital processing circuitry),availability of the processing resources, memory information (e.g.,type, size, availability, etc.), and/or any information germane toexecuting one or more tasks.

From these tables, the task distribution module 232 generates the DSTallocation information 242 to indicate where the data is stored, how topartition the data, where the task is stored, how to partition the task,which DT execution units should perform which partial task on which datapartitions, where and how intermediate results are to be stored, etc. Ifmultiple tasks are being performed on the same data or different data,the task distribution module factors such information into itsgeneration of the DST allocation information.

FIG. 30 is a diagram of a specific example of a distributed computingsystem performing tasks on stored data as a task flow 318. In thisexample, selected data 92 is data 2 and selected tasks are tasks 1, 2,and 3. Task 1 corresponds to analyzing translation of data from onelanguage to another (e.g., human language or computer language); task 2corresponds to finding specific words and/or phrases in the data; andtask 3 corresponds to finding specific translated words and/or phrasesin translated data.

In this example, task 1 includes 7 sub-tasks: task 1_1—identifynon-words (non-ordered); task 1_2—identify unique words (non-ordered);task 1_3—translate (non-ordered); task 1_4—translate back (ordered aftertask 1_3); task 1_5—compare to ID errors (ordered after task 1-4); task1_6—determine non-word translation errors (ordered after task 1_5 and11); and task 1_7—determine correct translations (ordered after 1_5 and1_2). The sub-task further indicates whether they are an ordered task(i.e., are dependent on the outcome of another task) or non-order (i.e.,are independent of the outcome of another task). Task 2 does not includesub-tasks and task 3 includes two sub-tasks: task 3_1 translate; andtask 3_2 find specific word or phrase in translated data.

In general, the three tasks collectively are selected to analyze datafor translation accuracies, translation errors, translation anomalies,occurrence of specific words or phrases in the data, and occurrence ofspecific words or phrases on the translated data. Graphically, the data92 is translated 306 into translated data 282; is analyzed for specificwords and/or phrases 300 to produce a list of specific words and/orphrases 286; is analyzed for non-words 302 (e.g., not in a referencedictionary) to produce a list of non-words 290; and is analyzed forunique words 316 included in the data 92 (i.e., how many different wordsare included in the data) to produce a list of unique words 298. Each ofthese tasks is independent of each other and can therefore be processedin parallel if desired.

The translated data 282 is analyzed (e.g., sub-task 3_2) for specifictranslated words and/or phrases 304 to produce a list of specifictranslated words and/or phrases 288. The translated data 282 istranslated back 308 (e.g., sub-task 1_4) into the language of theoriginal data to produce re-translated data 284. These two tasks aredependent on the translate task (e.g., task 1_3) and thus must beordered after the translation task, which may be in a pipelined orderingor a serial ordering. The re-translated data 284 is then compared 310with the original data 92 to find words and/or phrases that did nottranslate (one way and/or the other) properly to produce a list ofincorrectly translated words 294. As such, the comparing task (e.g.,sub-task 15) 310 is ordered after the translation 306 and re-translationtasks 308 (e.g., sub-tasks 1_3 and 1_4).

The list of words incorrectly translated 294 is compared 312 to the listof non-words 290 to identify words that were not properly translatedbecause the words are non-words to produce a list of errors due tonon-words 292. In addition, the list of words incorrectly translated 294is compared 314 to the list of unique words 298 to identify unique wordsthat were properly translated to produce a list of correctly translatedwords 296. The comparison may also identify unique words that were notproperly translated to produce a list of unique words that were notproperly translated. Note that each list of words (e.g., specific wordsand/or phrases, non-words, unique words, translated words and/orphrases, etc.) may include the word and/or phrase, how many times it isused, where in the data it is used, and/or any other informationrequested regarding a word and/or phrase.

FIG. 31 is a schematic block diagram of an example of a distributedstorage and task processing network (DSTN) module storing data and taskcodes for the example of FIG. 30. As shown, DS encoded data 2 is storedas encoded data slices across the memory (e.g., stored in memories 88)of DST execution units 1-5; the DS encoded task code 1 (of task 1) andDS encoded task 3 are stored as encoded task slices across the memory ofDST execution units 1-5; and DS encoded task code 2 (of task 2) isstored as encoded task slices across the memory of DST execution units3-7. As indicated in the data storage information table and the taskstorage information table of FIG. 29, the respective data/task has DSparameters of 3/5 for their decode threshold/pillar width; hencespanning the memory of five DST execution units.

FIG. 32 is a diagram of an example of distributed storage and task (DST)allocation information 242 for the example of FIG. 30. The DSTallocation information 242 includes data partitioning information 320,task execution information 322, and intermediate result information 324.The data partitioning information 320 includes the data identifier (ID),the number of partitions to split the data into, address information foreach data partition, and whether the DS encoded data has to betransformed from pillar grouping to slice grouping. The task executioninformation 322 includes tabular information having a taskidentification field 326, a task ordering field 328, a data partitionfield ID 330, and a set of DT execution modules 332 to use for thedistributed task processing per data partition. The intermediate resultinformation 324 includes tabular information having a name ID field 334,an ID of the DST execution unit assigned to process the correspondingintermediate result 336, a scratch pad storage field 338, and anintermediate result storage field 340.

Continuing with the example of FIG. 30, where tasks 1-3 are to bedistributedly performed on data 2, the data partitioning informationincludes the ID of data 2. In addition, the task distribution moduledetermines whether the DS encoded data 2 is in the proper format fordistributed computing (e.g., was stored as slice groupings). If not, thetask distribution module indicates that the DS encoded data 2 formatneeds to be changed from the pillar grouping format to the slicegrouping format, which will be done by the DSTN module. In addition, thetask distribution module determines the number of partitions to dividethe data into (e.g., 2_1 through 2_z) and addressing information foreach partition.

The task distribution module generates an entry in the task executioninformation section for each sub-task to be performed. For example, task1_1 (e.g., identify non-words on the data) has no task ordering (i.e.,is independent of the results of other sub-tasks), is to be performed ondata partitions 2_1 through 2_z by DT execution modules 1_1, 2_1, 3_1,4_1, and 5_1. For instance, DT execution modules 1_1, 2_1, 3_1, 4_1, and5_1 search for non-words in data partitions 2_1 through 2_z to producetask 1_1 intermediate results (R1-1, which is a list of non-words). Task1_2 (e.g., identify unique words) has similar task execution informationas task 1_1 to produce task 1_2 intermediate results (R1-2, which is thelist of unique words).

Task 1_3 (e.g., translate) includes task execution information as beingnon-ordered (i.e., is independent), having DT execution modules 1_1,2_1, 3_1, 4_1, and 5_1 translate data partitions 2_1 through 2_4 andhaving DT execution modules 1_2, 2_2, 3_2, 4_2, and 5_2 translate datapartitions 2_5 through 2_z to produce task 1_3 intermediate results(R1-3, which is the translated data). In this example, the datapartitions are grouped, where different sets of DT execution modulesperform a distributed sub-task (or task) on each data partition group,which allows for further parallel processing.

Task 1_4 (e.g., translate back) is ordered after task 1_3 and is to beexecuted on task 1_3's intermediate result (e.g., R1-3_1) (e.g., thetranslated data). DT execution modules 1_1, 2_1, 3_1, 4_1, and 5_1 areallocated to translate back task 1_3 intermediate result partitionsR1-3_1 through R1-3_4 and DT execution modules 1_2, 2_2, 6_1, 7_1, and7_2 are allocated to translate back task 1_3 intermediate resultpartitions R1-3_5 through R1-3_z to produce task 1-4 intermediateresults (R1-4, which is the translated back data).

Task 1_5 (e.g., compare data and translated data to identify translationerrors) is ordered after task 1_4 and is to be executed on task 1_4'sintermediate results (R4-1) and on the data. DT execution modules 1_1,2_1, 3_1, 4_1, and 5_1 are allocated to compare the data partitions (2_1through 2_z) with partitions of task 1-4 intermediate results partitionsR1-4_1 through R1-4_z to produce task 1_5 intermediate results (R1-5,which is the list words translated incorrectly).

Task 1_6 (e.g., determine non-word translation errors) is ordered aftertasks 1_1 and 1_5 and is to be executed on tasks 1_1's and 1_5'sintermediate results (R1-1 and R1-5). DT execution modules 1_1, 2_1,3_1, 4_1, and 5_1 are allocated to compare the partitions of task 1_1intermediate results (R1-1_1 through R1-1_z) with partitions of task 1-5intermediate results partitions (R1-5_1 through R1-5_z) to produce task1_6 intermediate results (R1-6, which is the list translation errors dueto non-words).

Task 1_7 (e.g., determine words correctly translated) is ordered aftertasks 1_2 and 1_5 and is to be executed on tasks 1_2's and 1_5'sintermediate results (R1-1 and R1-5). DT execution modules 1_2, 2_2,3_2, 4_2, and 5_2 are allocated to compare the partitions of task 1_2intermediate results (R1-2_1 through R1-2_z) with partitions of task 1-5intermediate results partitions (R1-5_1 through R1-5_z) to produce task1_7 intermediate results (R1-7, which is the list of correctlytranslated words).

Task 2 (e.g., find specific words and/or phrases) has no task ordering(i.e., is independent of the results of other sub-tasks), is to beperformed on data partitions 2_1 through 2_z by DT execution modules3_1, 4_1, 5_1, 6_1, and 7_1. For instance, DT execution modules 3_1,4_1, 5_1, 6_1, and 7_1 search for specific words and/or phrases in datapartitions 2_1 through 2_z to produce task 2 intermediate results (R2,which is a list of specific words and/or phrases).

Task 3_2 (e.g., find specific translated words and/or phrases) isordered after task 1_3 (e.g., translate) is to be performed onpartitions R1-3_1 through R1-3_z by DT execution modules 1_2, 2_2, 3_2,4_2, and 5_2. For instance, DT execution modules 1_2, 2_2, 3_2, 4_2, and5_2 search for specific translated words and/or phrases in thepartitions of the translated data (R1−3_1 through R1-3_z) to producetask 3_2 intermediate results (R3-2, which is a list of specifictranslated words and/or phrases).

For each task, the intermediate result information indicates which DSTunit is responsible for overseeing execution of the task and, if needed,processing the partial results generated by the set of allocated DTexecution units. In addition, the intermediate result informationindicates a scratch pad memory for the task and where the correspondingintermediate results are to be stored. For example, for intermediateresult R1-1 (the intermediate result of task 11), DST unit 1 isresponsible for overseeing execution of the task 1_1 and coordinatesstorage of the intermediate result as encoded intermediate result slicesstored in memory of DST execution units 1-5. In general, the scratch padis for storing non-DS encoded intermediate results and the intermediateresult storage is for storing DS encoded intermediate results.

FIGS. 33-38 are schematic block diagrams of the distributed storage andtask network (DSTN) module performing the example of FIG. 30. In FIG.33, the DSTN module accesses the data 92 and partitions it into aplurality of partitions 1-z in accordance with distributed storage andtask network (DST) allocation information. For each data partition, theDSTN identifies a set of its DT (distributed task) execution modules 90to perform the task (e.g., identify non-words (i.e., not in a referencedictionary) within the data partition) in accordance with the DSTallocation information. From data partition to data partition, the setof DT execution modules 90 may be the same, different, or a combinationthereof (e.g., some data partitions use the same set while other datapartitions use different sets).

For the first data partition, the first set of DT execution modules(e.g., 1_1, 2_1, 3_1, 4_1, and 5_1 per the DST allocation information ofFIG. 32) executes task 1_1 to produce a first partial result 102 ofnon-words found in the first data partition. The second set of DTexecution modules (e.g., 1_1, 2_1, 3_1, 4_1, and 5_1 per the DSTallocation information of FIG. 32) executes task 1_1 to produce a secondpartial result 102 of non-words found in the second data partition. Thesets of DT execution modules (as per the DST allocation information)perform task 1_1 on the data partitions until the “z” set of DTexecution modules performs task 1_1 on the “zth” data partition toproduce a “zth” partial result 102 of non-words found in the “zth” datapartition.

As indicated in the DST allocation information of FIG. 32, DST executionunit 1 is assigned to process the first through “zth” partial results toproduce the first intermediate result (R1-1), which is a list ofnon-words found in the data. For instance, each set of DT executionmodules 90 stores its respective partial result in the scratchpad memoryof DST execution unit 1 (which is identified in the DST allocation ormay be determined by DST execution unit 1). A processing module of DSTexecution 1 is engaged to aggregate the first through “zth” partialresults to produce the first intermediate result (e.g., R1_1). Theprocessing module stores the first intermediate result as non-DS errorencoded data in the scratchpad memory or in another section of memory ofDST execution unit 1.

DST execution unit 1 engages its DST client module to slice groupingbased DS error encode the first intermediate result (e.g., the list ofnon-words). To begin the encoding, the DST client module determineswhether the list of non-words is of a sufficient size to partition(e.g., greater than a Terabyte). If yes, it partitions the firstintermediate result (R1-1) into a plurality of partitions (e.g., R1-i_1through R1-1_m). If the first intermediate result is not of sufficientsize to partition, it is not partitioned.

For each partition of the first intermediate result, or for the firstintermediate result, the DST client module uses the DS error encodingparameters of the data (e.g., DS parameters of data 2, which includes3/5 decode threshold/pillar width ratio) to produce slice groupings. Theslice groupings are stored in the intermediate result memory (e.g.,allocated memory in the memories of DST execution units 1-5).

In FIG. 34, the DSTN module is performing task 1_2 (e.g., find uniquewords) on the data 92. To begin, the DSTN module accesses the data 92and partitions it into a plurality of partitions 1-z in accordance withthe DST allocation information, or it may use the data partitions oftask 1_1 if the partitioning is the same. For each data partition, theDSTN identifies a set of its DT execution modules to perform task 1_2 inaccordance with the DST allocation information. From data partition todata partition, the set of DT execution modules may be the same,different, or a combination thereof. For the data partitions, theallocated set of DT execution modules executes task 1_2 to produce apartial results (e.g., 1^(st) through “zth”) of unique words found inthe data partitions.

As indicated in the DST allocation information of FIG. 32, DST executionunit 1 is assigned to process the first through “zth” partial results102 of task 1_2 to produce the second intermediate result (R1-2), whichis a list of unique words found in the data 92. The processing module ofDST execution 1 is engaged to aggregate the first through “zth” partialresults of unique words to produce the second intermediate result. Theprocessing module stores the second intermediate result as non-DS errorencoded data in the scratchpad memory or in another section of memory ofDST execution unit 1.

DST execution unit 1 engages its DST client module to slice groupingbased DS error encode the second intermediate result (e.g., the list ofnon-words). To begin the encoding, the DST client module determineswhether the list of unique words is of a sufficient size to partition(e.g., greater than a Terabyte). If yes, it partitions the secondintermediate result (R1-2) into a plurality of partitions (e.g., R1-2_1through R1-2_m). If the second intermediate result is not of sufficientsize to partition, it is not partitioned.

For each partition of the second intermediate result, or for the secondintermediate results, the DST client module uses the DS error encodingparameters of the data (e.g., DS parameters of data 2, which includes3/5 decode threshold/pillar width ratio) to produce slice groupings. Theslice groupings are stored in the intermediate result memory (e.g.,allocated memory in the memories of DST execution units 1-5).

In FIG. 35, the DSTN module is performing task 1_3 (e.g., translate) onthe data 92. To begin, the DSTN module accesses the data 92 andpartitions it into a plurality of partitions 1-z in accordance with theDST allocation information or it may use the data partitions of task 1_1if the partitioning is the same. For each data partition, the DSTNidentifies a set of its DT execution modules to perform task 1_3 inaccordance with the DST allocation information (e.g., DT executionmodules 1_1, 2_1, 3_1, 4_1, and 5_1 translate data partitions 2_1through 2_4 and DT execution modules 1_2, 2_2, 3_2, 4_2, and 5_2translate data partitions 2_5 through 2_z). For the data partitions, theallocated set of DT execution modules 90 executes task 1_3 to producepartial results 102 (e.g., 1^(st) through “zth”) of translated data.

As indicated in the DST allocation information of FIG. 32, DST executionunit 2 is assigned to process the first through “zth” partial results oftask 1_3 to produce the third intermediate result (R1-3), which istranslated data. The processing module of DST execution 2 is engaged toaggregate the first through “zth” partial results of translated data toproduce the third intermediate result. The processing module stores thethird intermediate result as non-DS error encoded data in the scratchpadmemory or in another section of memory of DST execution unit 2.

DST execution unit 2 engages its DST client module to slice groupingbased DS error encode the third intermediate result (e.g., translateddata). To begin the encoding, the DST client module partitions the thirdintermediate result (R1-3) into a plurality of partitions (e.g., R1-3_1through R1-3_y). For each partition of the third intermediate result,the DST client module uses the DS error encoding parameters of the data(e.g., DS parameters of data 2, which includes 3/5 decodethreshold/pillar width ratio) to produce slice groupings. The slicegroupings are stored in the intermediate result memory (e.g., allocatedmemory in the memories of DST execution units 2-6 per the DST allocationinformation).

As is further shown in FIG. 35, the DSTN module is performing task 1_4(e.g., retranslate) on the translated data of the third intermediateresult. To begin, the DSTN module accesses the translated data (from thescratchpad memory or from the intermediate result memory and decodes it)and partitions it into a plurality of partitions in accordance with theDST allocation information. For each partition of the third intermediateresult, the DSTN identifies a set of its DT execution modules 90 toperform task 1_4 in accordance with the DST allocation information(e.g., DT execution modules 1_1, 2_1, 3_1, 4_1, and 5_1 are allocated totranslate back partitions R1-3_1 through R1-3_4 and DT execution modules1_2, 2_2, 6_1, 7_1, and 7_2 are allocated to translate back partitionsR1-3_5 through R1-3_z). For the partitions, the allocated set of DTexecution modules executes task 14 to produce partial results 102 (e.g.,1^(st) through “zth”) of re-translated data.

As indicated in the DST allocation information of FIG. 32, DST executionunit 3 is assigned to process the first through “zth” partial results oftask 1_4 to produce the fourth intermediate result (R1-4), which isretranslated data. The processing module of DST execution 3 is engagedto aggregate the first through “zth” partial results of retranslateddata to produce the fourth intermediate result. The processing modulestores the fourth intermediate result as non-DS error encoded data inthe scratchpad memory or in another section of memory of DST executionunit 3.

DST execution unit 3 engages its DST client module to slice groupingbased DS error encode the fourth intermediate result (e.g., retranslateddata). To begin the encoding, the DST client module partitions thefourth intermediate result (R1-4) into a plurality of partitions (e.g.,R1-4_1 through R1-4_z). For each partition of the fourth intermediateresult, the DST client module uses the DS error encoding parameters ofthe data (e.g., DS parameters of data 2, which includes 3/5 decodethreshold/pillar width ratio) to produce slice groupings. The slicegroupings are stored in the intermediate result memory (e.g., allocatedmemory in the memories of DST execution units 3-7 per the DST allocationinformation).

In FIG. 36, a distributed storage and task network (DSTN) module isperforming task 1_5 (e.g., compare) on data 92 and retranslated data ofFIG. 35. To begin, the DSTN module accesses the data 92 and partitionsit into a plurality of partitions in accordance with the DST allocationinformation or it may use the data partitions of task 1_1 if thepartitioning is the same. The DSTN module also accesses the retranslateddata from the scratchpad memory, or from the intermediate result memoryand decodes it, and partitions it into a plurality of partitions inaccordance with the DST allocation information. The number of partitionsof the retranslated data corresponds to the number of partitions of thedata.

For each pair of partitions (e.g., data partition 1 and retranslateddata partition 1), the DSTN identifies a set of its DT execution modules90 to perform task 1_5 in accordance with the DST allocation information(e.g., DT execution modules 1_1, 2_1, 3_1, 4_1, and 5_1). For each pairof partitions, the allocated set of DT execution modules executes task1_5 to produce partial results 102 (e.g., 1^(st) through “zth”) of alist of incorrectly translated words and/or phrases.

As indicated in the DST allocation information of FIG. 32, DST executionunit 1 is assigned to process the first through “zth” partial results oftask 1_5 to produce the fifth intermediate result (R1-5), which is thelist of incorrectly translated words and/or phrases. In particular, theprocessing module of DST execution 1 is engaged to aggregate the firstthrough “zth” partial results of the list of incorrectly translatedwords and/or phrases to produce the fifth intermediate result. Theprocessing module stores the fifth intermediate result as non-DS errorencoded data in the scratchpad memory or in another section of memory ofDST execution unit 1.

DST execution unit 1 engages its DST client module to slice groupingbased DS error encode the fifth intermediate result. To begin theencoding, the DST client module partitions the fifth intermediate result(R1-5) into a plurality of partitions (e.g., R1-5_1 through R1-5_z). Foreach partition of the fifth intermediate result, the DST client moduleuses the DS error encoding parameters of the data (e.g., DS parametersof data 2, which includes 3/5 decode threshold/pillar width ratio) toproduce slice groupings. The slice groupings are stored in theintermediate result memory (e.g., allocated memory in the memories ofDST execution units 1-5 per the DST allocation information).

As is further shown in FIG. 36, the DSTN module is performing task 1_6(e.g., translation errors due to non-words) on the list of incorrectlytranslated words and/or phrases (e.g., the fifth intermediate resultR1-5) and the list of non-words (e.g., the first intermediate resultR1-1). To begin, the DSTN module accesses the lists and partitions theminto a corresponding number of partitions.

For each pair of partitions (e.g., partition R1-1_1 and partitionR1-51), the DSTN identifies a set of its DT execution modules 90 toperform task 1_6 in accordance with the DST allocation information(e.g., DT execution modules 1_1, 2_1, 3_1, 4_1, and 5_1). For each pairof partitions, the allocated set of DT execution modules executes task1_6 to produce partial results 102 (e.g., 1^(st) through “zth”) of alist of incorrectly translated words and/or phrases due to non-words.

As indicated in the DST allocation information of FIG. 32, DST executionunit 2 is assigned to process the first through “zth” partial results oftask 1_6 to produce the sixth intermediate result (R1-6), which is thelist of incorrectly translated words and/or phrases due to non-words. Inparticular, the processing module of DST execution 2 is engaged toaggregate the first through “zth” partial results of the list ofincorrectly translated words and/or phrases due to non-words to producethe sixth intermediate result. The processing module stores the sixthintermediate result as non-DS error encoded data in the scratchpadmemory or in another section of memory of DST execution unit 2.

DST execution unit 2 engages its DST client module to slice groupingbased DS error encode the sixth intermediate result. To begin theencoding, the DST client module partitions the sixth intermediate result(R1-6) into a plurality of partitions (e.g., R1-6_1 through R1-6_z). Foreach partition of the sixth intermediate result, the DST client moduleuses the DS error encoding parameters of the data (e.g., DS parametersof data 2, which includes 3/5 decode threshold/pillar width ratio) toproduce slice groupings. The slice groupings are stored in theintermediate result memory (e.g., allocated memory in the memories ofDST execution units 2-6 per the DST allocation information).

As is still further shown in FIG. 36, the DSTN module is performing task1_7 (e.g., correctly translated words and/or phrases) on the list ofincorrectly translated words and/or phrases (e.g., the fifthintermediate result R1-5) and the list of unique words (e.g., the secondintermediate result R1-2). To begin, the DSTN module accesses the listsand partitions them into a corresponding number of partitions.

For each pair of partitions (e.g., partition R1-2_1 and partitionR1-51), the DSTN identifies a set of its DT execution modules 90 toperform task 1_7 in accordance with the DST allocation information(e.g., DT execution modules 1_2, 2_2, 3_2, 4_2, and 5_2). For each pairof partitions, the allocated set of DT execution modules executes task1_7 to produce partial results 102 (e.g., 1^(st) through “zth”) of alist of correctly translated words and/or phrases.

As indicated in the DST allocation information of FIG. 32, DST executionunit 3 is assigned to process the first through “zth” partial results oftask 1_7 to produce the seventh intermediate result (R1-7), which is thelist of correctly translated words and/or phrases. In particular, theprocessing module of DST execution 3 is engaged to aggregate the firstthrough “zth” partial results of the list of correctly translated wordsand/or phrases to produce the seventh intermediate result. Theprocessing module stores the seventh intermediate result as non-DS errorencoded data in the scratchpad memory or in another section of memory ofDST execution unit 3.

DST execution unit 3 engages its DST client module to slice groupingbased DS error encode the seventh intermediate result. To begin theencoding, the DST client module partitions the seventh intermediateresult (R1-7) into a plurality of partitions (e.g., R1-7_1 throughR1-7_z). For each partition of the seventh intermediate result, the DSTclient module uses the DS error encoding parameters of the data (e.g.,DS parameters of data 2, which includes 3/5 decode threshold/pillarwidth ratio) to produce slice groupings. The slice groupings are storedin the intermediate result memory (e.g., allocated memory in thememories of DST execution units 3-7 per the DST allocation information).

In FIG. 37, the distributed storage and task network (DSTN) module isperforming task 2 (e.g., find specific words and/or phrases) on the data92. To begin, the DSTN module accesses the data and partitions it into aplurality of partitions 1-z in accordance with the DST allocationinformation or it may use the data partitions of task 1_1 if thepartitioning is the same. For each data partition, the DSTN identifies aset of its DT execution modules 90 to perform task 2 in accordance withthe DST allocation information. From data partition to data partition,the set of DT execution modules may be the same, different, or acombination thereof. For the data partitions, the allocated set of DTexecution modules executes task 2 to produce partial results 102 (e.g.,1^(st) through “zth”) of specific words and/or phrases found in the datapartitions.

As indicated in the DST allocation information of FIG. 32, DST executionunit 7 is assigned to process the first through “zth” partial results oftask 2 to produce task 2 intermediate result (R2), which is a list ofspecific words and/or phrases found in the data. The processing moduleof DST execution 7 is engaged to aggregate the first through “zth”partial results of specific words and/or phrases to produce the task 2intermediate result. The processing module stores the task 2intermediate result as non-DS error encoded data in the scratchpadmemory or in another section of memory of DST execution unit 7.

DST execution unit 7 engages its DST client module to slice groupingbased DS error encode the task 2 intermediate result. To begin theencoding, the DST client module determines whether the list of specificwords and/or phrases is of a sufficient size to partition (e.g., greaterthan a Terabyte). If yes, it partitions the task 2 intermediate result(R2) into a plurality of partitions (e.g., R2_1 through R2_m). If thetask 2 intermediate result is not of sufficient size to partition, it isnot partitioned.

For each partition of the task 2 intermediate result, or for the task 2intermediate results, the DST client module uses the DS error encodingparameters of the data (e.g., DS parameters of data 2, which includes3/5 decode threshold/pillar width ratio) to produce slice groupings. Theslice groupings are stored in the intermediate result memory (e.g.,allocated memory in the memories of DST execution units 1-4, and 7).

In FIG. 38, the distributed storage and task network (DSTN) module isperforming task 3 (e.g., find specific translated words and/or phrases)on the translated data (R1-3). To begin, the DSTN module accesses thetranslated data (from the scratchpad memory or from the intermediateresult memory and decodes it) and partitions it into a plurality ofpartitions in accordance with the DST allocation information. For eachpartition, the DSTN identifies a set of its DT execution modules toperform task 3 in accordance with the DST allocation information. Frompartition to partition, the set of DT execution modules may be the same,different, or a combination thereof. For the partitions, the allocatedset of DT execution modules 90 executes task 3 to produce partialresults 102 (e.g., 1^(st) through “zth”) of specific translated wordsand/or phrases found in the data partitions.

As indicated in the DST allocation information of FIG. 32, DST executionunit 5 is assigned to process the first through “zth” partial results oftask 3 to produce task 3 intermediate result (R3), which is a list ofspecific translated words and/or phrases found in the translated data.In particular, the processing module of DST execution 5 is engaged toaggregate the first through “zth” partial results of specific translatedwords and/or phrases to produce the task 3 intermediate result. Theprocessing module stores the task 3 intermediate result as non-DS errorencoded data in the scratchpad memory or in another section of memory ofDST execution unit 7.

DST execution unit 5 engages its DST client module to slice groupingbased DS error encode the task 3 intermediate result. To begin theencoding, the DST client module determines whether the list of specifictranslated words and/or phrases is of a sufficient size to partition(e.g., greater than a Terabyte). If yes, it partitions the task 3intermediate result (R3) into a plurality of partitions (e.g., R3_1through R3_m). If the task 3 intermediate result is not of sufficientsize to partition, it is not partitioned.

For each partition of the task 3 intermediate result, or for the task 3intermediate results, the DST client module uses the DS error encodingparameters of the data (e.g., DS parameters of data 2, which includes3/5 decode threshold/pillar width ratio) to produce slice groupings. Theslice groupings are stored in the intermediate result memory (e.g.,allocated memory in the memories of DST execution units 1-4, 5, and 7).

FIG. 39 is a diagram of an example of combining result information intofinal results 104 for the example of FIG. 30. In this example, theresult information includes the list of specific words and/or phrasesfound in the data (task 2 intermediate result), the list of specifictranslated words and/or phrases found in the data (task 3 intermediateresult), the list of non-words found in the data (task 1 firstintermediate result R1-1), the list of unique words found in the data(task 1 second intermediate result R1-2), the list of translation errorsdue to non-words (task 1 sixth intermediate result R1-6), and the listof correctly translated words and/or phrases (task 1 seventhintermediate result R1-7). The task distribution module provides theresult information to the requesting DST client module as the results104.

FIG. 40A is a schematic block diagram of an embodiment of a dispersedstorage network (DSN) that includes a plurality of DSN entitiesincluding a dispersed storage (DS) processing module 350 and a pluralityof storage units 352. The DS processing module 350 may be implementedutilizing at least one of the distributed storage and task (DST)execution unit 36 of FIG. 1, a DST processing module, the DST processingunit 16 of FIG. 1, the user device 12 of FIG. 1, and a DS unit. Eachstorage unit 352 may be implemented utilizing the DST execution unit 36of FIG. 1.

The DSN functions to perform a plurality of tasks to facilitate storingdata 354 in some of the plurality of storage units 352 for subsequentretrieval. The storing includes the DS processing module 350 performingtasks of the plurality of tasks including encoding the data 354 using adispersed storage error coding function to produce slices 356 andstoring the slices 356 in at least a write threshold number of theplurality of storage units 352. The retrieval includes the DS processingmodule 350 performing other tasks of the plurality of tasks includingreceiving a data retrieval request, issuing slice requests to at least aread threshold number of the plurality of storage units 352, receivingslices 356, and decoding the slices 356 to produce reproduced data.

The DSN entities may generate provenance information 358 as theplurality of tasks are performed. The provenance information 358includes a plurality of primary information types, where a first primaryinformation type includes identity of the data, a second primaryinformation type includes timing information, a third primaryinformation type includes DSN entity identifiers, a fourth primaryinformation type includes error/integrity information, and a fifthprimary information type includes information about the data. Theprovenance information 358 is discussed in greater detail with referenceto FIG. 40B. The DS processing module 350 receives the provenanceinformation 358 from time to time as the plurality of tasks areperformed. The DS processing module 350 aggregates the provenanceinformation 358 to generate one or more provenance objects. The DSprocessing module three and 50 encodes each of the one or moreprovenance objects using the dispersed storage error coding function toproduce one or more sets of corresponding provenance slices 356 forstorage in at least a write threshold number of storage units of theplurality of storage units 352.

The provenance information 358 from the one or more provenance objectsmay be utilized from time to time by an analyzing DSN entity to producesummary information with regards to the performance of the plurality oftasks. The analyzing DSN entity includes at least one of a DS managingunit, the DSTN managing unit 18 of FIG. 1, a DS processing module, a DSTprocessing module, a DS processing unit, the DST processing unit 16 ofFIG. 1, and the user device 12 of FIG. 1. For example, the analyzing DSNentity recovers the provenance information 358 and sorts the provenanceinformation using the second primary information type of the timinginformation to identify a time based DSN error condition to produce thesummary information.

At least one of the DS processing module 350 and the analyzing DSNentity produces one or more dispersed hierarchical indexes to facilitaterecovering the provenance information 358 from the one or more storedprovenance objects. Each of the one or more dispersed hierarchicalindexes may be associated with one or more of the plurality ofinformation types. For example, a first dispersed hierarchical index isassociated with the first primary information type that includes theidentity of the data. As another example, a second dispersedhierarchical index is associated with the second primary informationtype that includes the timing information. The structure of the one ormore dispersed hierarchical indexes is discussed in greater detail withreference to FIG. 40C.

FIG. 40B is a diagram of an embodiment of a structure of a provenanceobject 360 that includes a data identifier (ID) field 362, a timewritten field 364, a time to write field 366, a storage unit IDs field368, a DS processing module ID field 370, an integrity information field372, a time of last integrity verification field 374, and the errorinformation field 376, and a data size field 378. The data ID field 362includes at least one of an object name of a data object, an objectnumber, and a dispersed storage network (DSN) ID. The time written field364 includes a timestamp associated with when a data object was writtenand when each slice of a set of slices was written. The time to writefield 366 includes a time duration of a time span associated with howlong a write sequence took to completion. The storage unit IDs field 368includes identifiers of each storage unit of a set of storage unitsutilized to store a set of encoded data slices and may further include astorage success indicator indicating whether a corresponding encodeddata slice of the set of encoded data slices was stored successfully.The DS processing module ID field 370 includes an identifier associatedwith a particular DS processing module associated with a task. Theintegrity information field 372 includes integrity information withregards to one or more of a data object, a data segment, and a dataslice. The integrity information includes at least one of an integrityvalue, a re-created integrity value, and an_integrity algorithm ID. Thetime of last integrity verification field 374 includes a timestamp andtree associated with when a last integrity verification task wasperformed with regards to a particular data segment and/or data slice.The error information field 376 includes an indicator with regards to anerror associated with a task. The data size field 378 includes a datasize entry associated with at least one of a size of the data object, asize of a data segment, and a size of an encoded data slice.

FIG. 40C is a diagram of an embodiment of a set of dispersedhierarchical indexes 1-N which may be utilized to index one or moreprovenance objects stored in a dispersed storage network (DSN). Eachdispersed hierarchical index includes a plurality of index nodesarranged in a plurality of levels where a top-level includes a rootindex node and a bottom level includes one or more leaf nodes as theindex nodes. Index nodes in a higher level above other index nodes at alower level may serve as a parent index nodes and the other index nodesat the lower-level serve as child index nodes to the parent index nodes.Index nodes at a common level serve as siblings index nodes to indexnodes at the common level. Leaf nodes may include a data object such asa provenance object and/or may include a DSN address associated with theprovenance object stored as a set of provenance slices within the DSN.For example, an index node of the dispersed hierarchical index 1 pointsto provenance object 1-1, and another index node of the dispersedhierarchical index 1 points to provenance object 1-2, etc. The indexnodes include a DSN address field that points to a storage locationwithin the DSN where associated index nodes are stored. For example, theDSN address field includes a DSN address associated with a sibling indexnode to the right and another DSN address associated with one or morechild index nodes.

The index nodes are further associated with a minimum index key value toassist in searching the dispersed hierarchical index structure toidentify a leaf node that corresponds to a desired provenance object.The dispersed hierarchical index may be searched using an index keyassociated with an attribute of a desired search and comparing the indexkey to minimum index key values associated with index nodes as searchingstarts with the root index node the top and proceeds in a downwarddirection within the structure to identify the leaf note thatcorresponds to the desired provenance object. A series of retrievals ofsets of encoded index slices from the DSN may be required to recoverindex nodes along a search path from the root index node to the leafnode associated with the desired provenance object. Two or moredispersed hierarchical indexes of the set of dispersed hierarchicalindexes may include entries within leaf nodes that point to a commonprovenance object when two or more attributes of the common provenanceobject are associated with two or more index keys utilized whensearching the two or more dispersed hierarchical indexes. For example,an index node of the dispersed hierarchical index 1 points and anotherindex node of the dispersed hierarchical index N both point toprovenance object 1-4.

FIG. 40D is a flowchart illustrating an example of generating provenanceinformation. The method begins with step 380 where a processing module(e.g., of a dispersed storage (DS) processing module, a distributedstorage and task (DST) client module) receives data for storage in adispersed storage network (DSN). The receiving may include receiving adata identifier of the data and a requesting entity identifier. Themethod continues at step 382 where the processing module issues writeslice requests to the DSN to facilitate storage of the data in the DSN.The issuing includes encoding the data to produce slices, generatingwrite slice requests to include the slices, selecting storage units ofthe DSN, outputting the write slice requests to the selected storageunits, and generating timestamps associated with the outputting tocontribute to the provenance information.

The method continues at step 384 where the processing module obtainsprovenance information from one or more DSN entities of the DSN withregards to storage of the data in the DSN. The obtaining includes atleast one of initiating a query, receiving the provenance information,performing a lookup, and generating the provenance information. Theprocessing module may utilize a provenance information template based onone or more of a data type of the data, the requesting entity ID, a datasize indicator, an error message, a historical performance record, andany other factor associated with storage of the data. For example, theprocessing module determines to utilize a provenance informationtemplate associated with timestamps of each step of sending slicesacross the network when the data type indicates a videotape and ahistorical performance record indicates that previous storage timinglatency was unfavorable.

The method continues at step 386 where the processing module generates aprovenance object using the provenance information. The generatingincludes one or more of aggregating the provenance information andgenerating additional provenance information based on the obtainedprovenance information. For example, the processing module calculates atime for completion of a task. The method continues at step 388 wherethe processing module stores the provenance object in the DSN. Thestoring includes encoding the provenance object to produce provenanceslices and sending the provenance slices to the DSN for storage at aprovenance object DSN address.

The method continues at step 390 where the processing module identifiesone or more dispersed hierarchical indexes associated with theprovenance object. The identifying includes selecting the one or moredispersed hierarchical indexes based on an index template associatedwith the provenance information. For example, the processing moduleselects a time delay index when time delay is included in the provenanceinformation and selects a DSN addressing index when the provenanceobject DSN address falls within a DSN address range associated with theindex template. The method continues at step 392 where the processingmodule updates the identified one or more dispersed hierarchical indexesto include an entry associated with the provenance object. The updatingincludes generating an index key associated with the provenanceinformation, generating the entry to include the provenance objectand/or the provenance object DSN address and the index key, accessing acorresponding dispersed hierarchical indexes the one or more dispersedhierarchical indexes index using the index key to identify and recoveran index node for updating (e.g., a leaf node), and updating therecovered index node to include the entry (e.g., modify and store in theDSN).

FIG. 41 is a flowchart illustrating an example of identifying apotential error within a dispersed storage network (DSN) as discussedwith reference to FIG. 40A. The method begins with step 400 where aprocessing module (e.g., of a distributed storage and task (DST) clientmodule, of a dispersed storage (DS) processing module) identifies one ormore dispersed hierarchical indexes associated (e.g., as discussed withreference to FIGS. 40A-D) with provenance information for a set ofstorage units of the DSN. The identifying includes determining an errortype of interest (e.g., initiating a query, receiving the error type ofinterest, performing a lookup, interpreting one or more error messagesto produce the error type) and selecting the one or more dispersedhierarchical indexes based on the error type of interest and an indextype. For example, the processing module selects an index associatedwith missing slices when the error type of interest includesunsuccessfully stored slices.

The method continues at step 402 where the processing module generatesone or more index keys associated with the provenance information. Thegenerating includes identifying one or more search attributes (e.g.,time, a data identifier, a slice name, data type, a DSN entityidentifier) based on one or more of the error type of interest and theone or more dispersed hierarchical indexes and selecting the one or moreindex keys based on the identified search attributes. For example, theprocessing module generates one or more index keys associated with aparticular set of storage units of the DSN and a particular timeframe.

The method continues at step 404 where the processing module accessesthe identified one or more dispersed hierarchical indexes utilizing theone or more index keys to access one or more provenance objects thatincludes the provenance information. The accessing includes searchingeach of the one or more identified dispersed hierarchical indexes usinga corresponding index key of the one or more index keys to identify anindex entry and retrieving a corresponding provenance object from theDSN based on a provenance object DSN address extracted from the indexentry (e.g., issue read slice requests using the provenance object DSNaddress, receive slices, and decode the slices to reproduce thecorresponding provenance object). Alternatively, the accessing includesextracting the provenance object directly from the identified indexentry when the provenance object is available from the identified indexentry.

For each storage unit of the set of storage units, the method continuesat step 406 where the processing module compares provenance informationassociated with the storage unit to other provenance information. Thecomparing includes at least one of comparing the provenance informationof the storage unit to similar provenance information of at least oneother storage unit of the set of storage units and comparing theprovenance information of the storage unit to an average valueassociated with provenance information of the set of storage units. Forexample, the processing module compares a latency time of the storageunit to an average latency time of the set of storage units.

The method continues at step 408 where the processing module identifiesa potential error based on the comparison. The identifying includesindicating an error when the provenance information of the storage unitcompares unfavorably (e.g., greater than a threshold value difference)to the similar provenance information of the at least one other storageunit. For example, the processing module indicates a potential errorassociated with writing slices when the comparison indicates that the atleast one other storage unit has performed more slice writing taskswithin a particular timeframe than that of the storage unit. As anotherexample, the processing module indicates potential missing slices as thepotential errors when the comparison indicates that the storage unit wasoff line when the potential missing slices were written to the set ofstorage units. Still further examples of potential errors includes oneor more of identifiers of storage units with an error, and identity of amemory device associated with an error, and a DSN address range to bescanned for slice errors.

FIG. 42A is a diagram of another embodiment of a dispersed storagenetwork (DSN) that includes a store module 410, a storage unit sets 1-2,and a retrieve module 412. The DSN may include any number of storageunit sets. The store module 410 and the retrieve module 412 may beimplemented utilizing one or more of a dispersed storage (DS) processingmodule, a DS processing unit, a distributed storage and task (DST)processing module, the DST processing unit 16 of FIG. 1, and the userdevice 12 of FIG. 1. Each of the storage unit sets includes a set ofstorage units 352, where a number of storage units of each storage unitset is in accordance with a unique set of dispersal parametersassociated with the storage unit set. Each set of dispersal parametersfor the storage unit sets 1-2 is established to meet particularperformance, reliability, and availability goals for storage andretrieval of data. For example, storage unit set 1 includes 16 storageunits and storage unit set 2 includes three storage units when a pillarwidth of a first set of dispersal parameters associated with storageunit set 1 is 16 and a pillar width of a second set of dispersalparameters associated with storage unit set 2 is 3. In such an example,the pillar width of 16 may be established when a goal associated withstorage unit set 1 includes higher than average storage availability andhigher than average retrieval reliability and the pillar width of 3 maybe established when a goal associated with storage unit set 2 includesminimizing input/output operations within the DSN to store and retrievethe data.

The DSN functions to receive data 414, store the data 414 in the storageunit sets, 1-2 and subsequently retrieve the data from the storage unitsets as recovered data 416. The store module 410 performs a series ofsteps to store the data 414 in the storage unit sets and the retrievemodule 412 performs another series of steps to subsequently retrieve thedata from the storage unit sets to produce the recovered data 416.

In an example of operation, the store module 410 receives the data 414for storage (e.g., a data segment of the plurality of data segments of adata object) and encodes the data 414 using a dispersed storage errorcoding function and in accordance with the first set of dispersalparameters associated with the storage unit set 1 to produce slice set 1of encoded data slices. The store module 410 outputs the slice set 1 tothe storage unit set 1 for storage.

Having stored the data as the sliced set 1 in the storage unit set 1,the store module 410 generates a representation of the data to includeat least one of the data, a compressed version of the data, a redactedversion of the data, and a transformed version of the data. The storemodule 410 encodes the representation of the data using the dispersedstorage error coding function and in accordance with the second set ofencoded dispersal parameters associated with the storage unit set 2 toproduce a slice set 2. For example, the store module 410 encodes therepresentation of the data to generate a set of three slices as sliceset 2. The store module 410 outputs the slice set 2 to the storage unitset 1 for storage. The store module 410 updates one or more of adispersed hierarchical index and a directory to include addressinginformation (e.g., a data ID, a data ID for the representation of thedata, and one or more DSN addresses).

The retrieve module 412, when retrieving the data, identifies two ormore sets of encoded data slices stored in two or more storage unit setsof the DSN. The retrieve module 412 selects one of the two or more setsof encoded data slices based on one or more of a predetermination, a DSNactivity level, a reliability requirement, a timing performancerequirements, and a bandwidth requirement. The selecting includesidentifying the unique sets of dispersal parameters corresponding toeach of the two or more sets of encoded data slices (e.g., a vaultlookup, a registry information look up, initiating a query, receivingdispersal parameters) and selecting the one of the two or more sets ofencoded data slices based on a corresponding unique set of dispersalparameters associated with the one of the two or more sets of encodeddata slices. For example, the retrieve module 412 selects a unique setof dispersal parameters with a lowest pillar width when the DSN activitylevel indicates an above average level of activity. As another example,the retrieve module selects another unique set of dispersal parameterswith a highest pillar width when the DSN activity level indicates abelow-average level of activity and the reliability requirement includesa higher than average level of required reliability.

The retrieve module 412 determines whether at least a decode thresholdnumber of encoded data slices of the selected set of encoded data slicesare recoverable from a corresponding storage unit set. The determiningincludes at least one of issuing a list request, receiving a listresponse, issuing read slice requests, and receiving read sliceresponses that includes at least one of a retrieved slice set 1 and aretrieved slice set 2. When the decode threshold number of encoded dataslices are recoverable, the retrieve module 412 decodes the at least thedecode threshold number of retrieved encoded data slices using thedispersed storage error coding function and in accordance with theselected unique set of dispersal parameters to produce the recovereddata 416. When the decode threshold number of encoded data slices arenot recoverable, the retrieve module 412 selects another set of encodeddata slices of the two or more sets of encoded data slices retrieves atleast a decode threshold number of encoded data slices of the other setof encoded data slices, and decodes the at least the decode thresholdnumber of encoded data slices of the other set of encoded data slicesusing the dispersed storage error coding function and in accordance witha corresponding unique set of dispersal parameters to produce therecovered data. The selecting the other set of encoded data slicesincludes selecting a next best set of unique set of dispersal parametersassociated with the other set of encoded data slices. For example, theretrieve module selects the slice set 1 associated with the pillar widthof 16 as the other set of encoded data slices.

FIG. 42B is a flowchart illustrating an example of accessing data. Themethod begins to store data with step 418 where a processing module(e.g., of a store module, of a retrieve module, of a distributed storageand task (DST) client module) encodes data using a dispersed storageerror coding function in accordance with a first set of dispersalparameters to produce a first set of encoded data slices. The encodingmay further include segmenting a data object to produce a plurality ofdata segments and encoding a first data segment of the plurality of datasegments. The method continues at step 420 where the processing modulestores the first set of encoded data slices in a first storage unit set.The storing includes generating a set of slice names, generating a setof write slice requests that includes the set of slice names and thefirst set of encoded data slices, and outputting the set of write slicerequests to the first storage unit set.

The method continues at step 422 where the processing module transformsthe data to produce a representation of the data. The transformingincludes applying at least one of a null transformation, a compressionalgorithm, a redacting algorithm, an encryption algorithm, adeterministic function, and an interleaving function. The methodcontinues at step 424 where the processing module encodes therepresentation of the data using the dispersed storage error codingfunction and in accordance with a second set of dispersal parameters toproduce a second set of encoded data slices.

The method continues at step 426 where the processing module stores thesecond set of encoded data slices in a second storage unit set. Themethod continues at step 428 where the processing module updates one ormore of a dispersed hierarchical indexes in a directory with regards tostorage of the first and second sets of encoded data slices. Theupdating includes associating dispersed storage network (DSN) addressesof the first and second sets of encoded data slices with an identifierof the data.

The method continues, when retrieving data, at step 430 where, for eachdata segment of the plurality data segments, the processing moduleidentifies two or more sets of encoded data slices. The identifyingincludes at least one of accessing the dispersed hierarchical index andaccessing the directory to identify two or more DSN addresses associatedwith the two or more sets of encoded data slices. The method continuesat step 432 where the processing module selects one of the two or moresets of encoded data slices. The selecting includes identifying a DSNaddress of a set of encoded data slices associated with an expectedperformance level that compares favorably to a desired performance level(e.g., a smallest width when minimizing input/output operations).

The method continues at step 434 where the processing module determineswhether at least a decode threshold number of encoded data slices of theselected set of encoded data slices are retrievable (e.g., a listslices, attempting to retrieve slices). The method branches to step 438when the at least the decode threshold number of encoded data slices ofthe selected set of encoded data slices are not retrievable. The methodcontinues to step 436 when the at least the decode threshold number ofencoded data slices of the selected set of encoded data slices areretrievable. The method continues at step 436 where the processingmodule decodes a decode threshold number of retrieved encoded dataslices using the dispersed storage error coding function and inaccordance with dispersal parameters associated with the selected set ofencoded data slices to reproduce the data.

When the at least the decode threshold number of encoded data slices ofthe selected set of encoded data slices are not retrievable, the methodcontinues at step 438 where the processing module selects another of thetwo or more sets of encoded data slices. The selecting includesidentifying another DSN address of the other set of encoded data slicesassociated with an expected performance level that compares mostfavorably to the desired performance level (e.g., a next smallest widthwhen minimizing input/output operations). The method continues at step440 where the processing module decodes the decode threshold number ofother retrieved encoded data slices using the dispersed storage errorcoding function and in accordance with dispersal parameters associatedwith the other set of encoded data slices to reproduce the data.Alternatively, or in addition to, the method may continue in a similarfashion to try as many of the two or more sets of encoded data slices toobtain at least a decode threshold number of encoded data slices.

FIG. 43A is a diagram of another embodiment of a dispersed storagenetwork (DSN) that includes a storing entity 442, a retrieving entity444, the distributed storage and task (DST) client module 34 of FIG. 1,and the distributed storage and task network (DSTN) module 22 of FIG. 1.The storing entity 442 and retrieving entity 444 may be implementedutilizing one or more of a DS processing module, a DS processing unit, aDST processing module, the DST processing unit 16 of FIG. 1, the userdevice 12 of FIG. 1, a storage unit, a storage device, the DST executionunit 36 of FIG. 1, and a DS unit. The DSTN module 22 includes theplurality of DST execution units 36 of FIG. 1. The DST client module 34includes a plurality of the outbound DST processing s 80 of FIG. 3, adata permuter 446, name permuters 448-450, and the inbound DSTprocessing 82 of FIG. 3.

The DSN functions to store data 92 and one or more permutations (1-N) ofthe data in the DSTN module 22 and retrieves at least one of the dataand one of the one or more permutations of the data from the DSTN module22 to produce recovered data 462. The one or more permutations of thedata provides reliable storage of variations of the data when thevariations of the data may be desired for subsequent retrieval. Suchvariations of the data includes rescaling images, reformatting video,compressing data files, converting data files from a first industrystandard format to a second industry standard format, etc.

The DSN stores the data 92 and the one or more permutations of the datain the DSN module 22 through a series of steps performed by the DSTclient module 34. The DST client module 34 obtains N permutationfunctions 454 based on at least one of a lookup, a predetermination,initiating a query, and receiving, and based on a type of data. Thepermutation functions includes at least one of a compression function, arescaling function, a transformation function, a redacting function, andinterleaving function, a reformatting function, and any other functionto provide a variation of the data.

The name permuted 448 permutes a received data name 452 based on thepermutation functions to produce a set of permuted data names 1-N. Forexample, the name permuted 448 performs a deterministic function on thedata name 452 in accordance with each permutation function to producethe set of N permuted data names. The deterministic function includes atleast one of a hashing function, a hash-based message authenticationcode, a mask generating function, a logical function, an arithmeticfunction, and a sponge function. For example, the name permuter 448performs a hashing function on the data name 452 to produce anintermediate hash value and adds the intermediate hash value to the dataname 452 to produce a first permuted data name of N permuted data names.

For each permutation function of the N permutation functions, the datapermuter 446 permutes the data 92 using the permutation function 454 toproduce a corresponding permuted data (e.g., PERMDAT1 through PERMDATN).For example, the data permuter permutes the data 92 using an imagecompression function to produce the PERMDATA1 and permutes the data 92using another image compression function (e.g., a further level ofcompression compared to the image compression function) to producePERMDATA2.

For each of the data 92 and the permuted data 1-N, a correspondingoutbound DST processing 80 encodes the data and each of the permuteddata 1-N to produce a slice groupings 96 and permuted data 1-N slicegroupings. Each of the outbound DST processing 80 output correspondingslice groupings to the DSTN module 22 for storage using the data name452 and the permuted data names 1-N. For example, a first outbound DSTprocessing 80 encodes the data 92 to produce the slice groupings 96,generates a set of slice names based on the data name 452, generates aset of write slice requests that includes the slice groupings 96 and setof slice names, and outputs the set of write slice requests to the DSTNmodule 22. As another example, a second outbound DST processing 80encodes PERMDATA1 to produce the permuted data 1 slice groupings,generates another set of slice names based on permuted data name 1,generates another set of write slice requests that includes the permuteddata 1 slice groupings and other set of slice names, and outputs theother set of write slice requests to the DSTN module 22.

The DSN retrieves the at least one of the data and the one of the one ormore permutations of the data from the DSTN module 22 to produce therecovered data 462 by a series of steps performed by the DST clientmodule 34. The name permuter 450 uses a received permutation function456 from the retrieving entity 444 and the data name 452 from theretrieving entity 444 to deterministically generate a permuted data name458 as previously discussed. The inbound DST processing 82 issues slicerequests 460 to the DSTN module 22 based on the permuted data name 458.The issuing includes generating a set of slice names based on thepermuted data name, generating a set of read slice requests thatincludes the set of slice names, and outputting the set of read slicerequests to the DSTN module 22.

The inbound DST processing 82 receives corresponding permuted data Xslice groupings (e.g., which may include at least some of slicegroupings 96 when the permutation function is a function to retrieve thedata 92). The inbound DST processing 82 decodes the permuted data Xslice groupings using the dispersed storage error coding function toproduce the recovered data 462.

FIG. 43B is a flowchart illustrating an example of accessing permuteddata. The method begins, when storing data, with step 464 where aprocessing module (e.g., of a distributed storage and task (DST) clientmodule, of a dispersed storage (DS) processing module) obtainspermutation functions. The method continues at step 466 where theprocessing module permutes a data name based on the permutationfunctions to produce permuted data names. The permuting of the data nameincludes performing a deterministic function on one or more of the dataname and an attribute of a permutation function. For each of thepermutation functions, the method continues at step 468 where theprocessing module permutes the data to produce corresponding permuteddata. The permuting includes performing the permutation function on thedata to produce the corresponding permuted data. The method continues atstep 470 where the processing module encodes the data using a dispersedstorage error coding function to produce a slice grouping.

The method continues at step 472 where the processing module encodeseach permuted data using the dispersed storage error coding function toproduce corresponding permuted slice groupings. The method continues atstep 474 where the processing module stores the slice grouping in adispersed storage network (DSN) memory using a DSN address correspondingto the data name. The storing includes generating at least one set ofslice names based on the DSN address, generating at least one set ofwrite slice requests that includes the at least one set of slice namesand the slice grouping, and sending the at least one set of write slicerequest to the DSN memory.

For each permuted slice grouping, the method continues at step 476 wherethe processing module stores the permuted slice grouping in the DSNmemory using another DSN address corresponding to a permuted data nameassociated with the permuted slice grouping. The storing includesdetermining the other DSN address based on the permuted data name,generating slice names based on the other DSN address, generating otherwrite slice requests to include the slice names of the other DSN addressand the permuted slice grouping, and outputting the other write slicerequests to the DSN memory.

The method continues, when retrieving data, with step 478 where theprocessing module receives a data name and an indicated permutationfunction with regards to retrieving at least one of correspondingpermuted data and data associated with the data name. The methodcontinues at step 480 where the processing module permutes the receiveddata name using the indicated permutation function to produce a permuteddata name. The permuting may include performing a null permutation whenrecovering the data.

The method continues at step 482 where the processing module issuesslice requests to the DSN memory based on the permuted data name. Theissuing includes generating slice names based on the permuted data name,generating read slice requests that includes the slice names, andoutputting the read slice requests to the DSN memory. The methodcontinues at step 484 where the processing module receives a data slicegrouping from the DSN. The data slice grouping includes at least one ofa permuted slice grouping associated with the permuted data and a slicegrouping associated with the data. The method continues at step 486where the processing module decodes the data slice grouping from the DSNmemory using the dispersed storage error coding function to producerecover data.

FIG. 44A is a diagram of another embodiment of a dispersed storagenetwork (DSN) that includes a requesting entity 500, the distributedstorage and task (DST) client module 34 of FIG. 43A, and the distributedstorage and task network (DSTN) module 22 of FIG. 1. The requestingentity 500 may be implemented utilizing one or more of a DS processingmodule, a DS processing unit, a DST processing module, the DSTprocessing unit 16 of FIG. 1, the user device 12 of FIG. 1, a storageunit, a storage device, the DST execution unit 16 of FIG. 1, and a DSunit. The DSTN module 22 includes the plurality of DST execution units36 of FIG. 1. The DST client module 34 includes the data permuter 446 ofFIG. 43A, the name permuter 448 of FIG. 43A, the inbound DST processing82 of FIG. 3 and the outbound DST processing 80 of FIG. 3.

The DSN functions to produce one or more permutations (1-N) of data 92recovered from storage within the DSTN module 22 and may function tostore permuted data 502 in the DSTN module 22 once produced tofacilitate immediate subsequent retrieval without a need to regeneratethe permuted data 502. The one or more permutations of the data providesvariations of the data when the variations of the data may be desired.Such variations of the data includes rescaled images, reformattingvideo, compressed data files, converted data files from a first industrystandard format to a second industry standard format, etc.

The DSN produces the data permutation by a series of steps performed bythe DST client module 34. The DST client module 34 receives a requestfor the permuted data that includes a data name 452 and a permutationfunction 456. The DST client module 34 determines whether the permuteddata is already stored within the DSTN module 22. The determiningincludes the name permuter 448 permuting the data name 452 based on thepermutation function to produce a permuted data name 458, the inboundDST processing 82 generating slice names based on the permuted data name458, the inbound DST processing 82 generating at least one of a set oflist slice requests and a set of read slice requests 460 that includesthe slice names, the inbound DST processing 82 outputting the at leastone of the set of lists slice request and the set of read slice requests460 to the DSTN module 22, and the inbound DST processing 82 receivingresponses that includes slice groupings 96. Alternatively, thedetermining includes accessing at least one of a directory and adispersed hierarchical index utilizing the permuted data name todetermine whether the permuted data has already been stored within theDSTN module.

When the permuted data has not already been stored within the DSTNmodule, the inbound DST processing 82 recovers the data 92 from the DSTNmodule. The recovering includes generating the slice names using thepermuted data name 458, generating read slice requests 460 that includesthe slice names, sending the read slice requests 460 to the DSTN module22, receiving slice groupings 96 from the DSTN module 22, decoding theslice groupings 96 using a dispersed storage error coding function toreproduce the data 92. The data permuted 446 permutes the data 92 usingthe permutation function to produce the permuted data 502.

When storing the permuted data 502 in the DSTN module 22, the outboundDST processing 80 encodes the permuted data 502 using the dispersedstorage error coding function to produce a permuted data X slicegrouping, generates permuted slice names based on the permuted dataname, generates one or more sets of write slice requests that includesthe permuted slice names and the permuted data slice grouping, andoutputs the one or more sets of write slice requests to the DSTN module22

FIG. 44B is a flowchart illustrating another example of accessingpermuted data. The method begins with step 504 where a processing module(e.g., of a distributed storage and task (DST) client module, of adispersed storage (DS) processing module) receives a request forpermuted data of data stored in a dispersed storage network (DSN). Therequest includes a data name and a permutation function identifier (ID).The method continues at step 506 where the processing module determineswhether the permuted data is recoverable from slices stored in the DSN.The determining includes permuting the data name to produce a permuteddata name, generating a permuted data DSN address using the permuteddata name, generating permuted slice names using the permuted data DSNaddress, issuing read slice requests to the DSN that includes thepermuted slice names, receiving responses, and indicating that thepermuted data is recoverable when the responses are favorable (e.g.,favorable when the slices of the permuted data are stored in the DSN).Alternatively, the processing module accesses at least one of adispersed hierarchical index and a directory to determine whether thepermuted DSN address exists.

When the permuted data is not recoverable from the slices stored in theDSN, the method continues at step 508 where the processing modulerecovers the data stored in the DSN from the slices stored in the DSN.The recovering includes generating a data DSN address using the dataname, issuing read slice requests to the DSN that includes a data slicenames based on the data DSN address, and decoding the retrieved dataslices from received read slice responses to reproduce the data. Themethod continues at step 510 where the processing module permutes thedata based on the permutation function identifier to produce thepermuted data. For example, the processing module accesses a table ofpermutation functions using the permutation function identifier andperforms the permutation function on the reproduce data to produce thepermuted data. The method continues at step 512 where the processingmodule permutes the data name of the data using a deterministic functionbased on the permutation function to produce a permuted data name. Forexample, the processing module performs an exclusiveOR function on aportion of the data name and a portion of the identifier of thepermutation function to produce the permuted data name.

The method continues at step 514 where the processing module encodes thepermuted data using a dispersed storage error coding function to producea permuted data slice grouping. The method continues at step 516 wherethe processing module generates a permuted data DSN address using thepermuted data name. For example, the processing module obtains a new DSNaddress for the permuted data name. The obtaining may include updatingat least one of a dispersed hierarchical index and a directory toindicate an association between the permuted data name and the new DSNaddress for the permuted data name. The method continues at step 518where the processing module stores the permuted data slice grouping inthe DSN using the permuted data slice DSN address. The storing includesgenerating permuted slice names using the permuted DSN address,generating write slice requests that includes the permuted slice namesand the permuted data slice grouping, and outputting the write slicerequests to the DSN.

FIGS. 45A-D are diagrams of another embodiment of a dispersed storagenetwork (DSN) illustrating an example of rebuilding data. The DSNincludes the distributed storage and task (DST) client module 34 of FIG.1, the network 24 of FIG. 1, and a DST execution unit set 520. The DSTexecution unit set 520 includes a set of DST execution units 1-8.Alternatively, the DST execution unit set 520 may include any number ofDST execution units. Hereafter, the DST execution unit may be referredto interchangeably as a storage unit of a set of storage units. Each DSTexecution unit may be implemented utilizing the DST execution unit 36 ofFIG. 1. The DST client module 34 includes the outbound DST processing 80of FIG. 3 and the inbound DST processing 82 of FIG. 3. The outbound DSTprocessing 80 includes the DS error encoding 112 of FIG. 4. The inboundDST processing 82 includes the DS error decoding 182 of FIG. 13 and anerror detector 522. The error detector 522 may be implemented utilizingthe processing module 84 of FIG. 3.

The DST client module 34 further includes a dispersed storage (DS)module. The DS module may be implemented utilizing a plurality ofprocessing modules. For instance, the plurality of processing modulesmay include the processing module 84 of FIG. 3. As a specific example,the plurality of processing module includes a first module, a secondmodule, a third module, a fourth module, a fifth module, and a sixthmodule.

The DSN functions to rebuild data associated with storage errors, wheredata is stored in the DST execution unit set 520. In an example of thestoring of the data, DST client module 34 encodes a data segment inaccordance with a dispersed storage error coding function to produce aset of encoded data slices (e.g., slices 1-8) and facilitates storage ofthe set of encoded data slices in the set of DST execution units 1-8(e.g., set of storage units). The set of encoded data slices include atotal number of encoded data slices. When subsequently retrieving thedata segment, at least a decode threshold number of encoded data slicesof the set of encoded data slices is required to recover the datasegment, where the decode threshold number is less than the totalnumber. A storage error includes at least one of a missing encoded dataslice, a corrupted encoded data slice, and a missing revision of andencoded data slice.

FIG. 45A illustrates initial steps of the example of the rebuilding ofthe data, where the inbound DST processing 82 sends, via the network 24,representations of a read-rebuild inquiry request to storage units ofthe DSN, where the storage units collectively store the set of encodeddata slices and where the data segment was encoded in accordance withthe dispersed storage error coding function to produce the set ofencoded data slices. As a specific example, the inbound DST processing82 receives a read data request 524 that includes a data segment readrequest. Having received the data segment read request, the inbound DSTprocessing 82 processes the data segment read request to produce theread-rebuild inquiry request. For example, the inbound DST processing 82identifies the data segment based on the data segment read request andgenerates a DSN addressing information (e.g., generates a set of slicenames) based on the identified data segment.

The sending of the representations of the read-rebuild inquiry requestincludes generating the representations of the read-rebuild inquiryrequest. As a specific example of the generating of the representationsof the read-rebuild inquiry request, the inbound DST processing 82generates read requests regarding a read threshold number of encodeddata slices of the set of encoded data slices, where the read thresholdnumber is less than the total number and equal to or greater than thedecode threshold number. For instance, the inbound DST processing 82generates read slice requests 1-6, where the read slice requests 1-6includes slice names of the set of slice names that corresponds toencoded data slices 1-6 when the read threshold is 6.

Having generated the read requests, the inbound DST processing 82generates status check requests regarding a difference number of encodeddata slices of the set of encoded data slices, where the differencenumber is equal or less than a difference between the total number andthe read threshold number. For example, the inbound DST processing 82generates check slice requests 7-8, where the check slice requests 7-8includes slice names of the set of slice names that corresponds toencoded data slices 7-8 when the total number is 8 and the readthreshold number is 6.

Having generated the read requests and the status check request, theinbound DST processing 82 sends the read requests and a status checkrequests to the set of DST execution units 1-8. For example, the inboundDST processing 82 sends, via the network 24, the read slice requests 1-6to DST execution units 1-6 and the inbound DST processing 82 sends, viathe network 24, the check slice requests 7-8 to the DST execution units7-8.

Alternatively, or in addition to, after sending the representations ofthe read-rebuild inquiry request and when another data segment readrequest for the data segment is not received prior to expiration of astatus check time out period, the inbound DST processing 82 sends, viathe network 24, status check requests regarding the set of encoded dataslices to the set of DST execution units 520. For example, the inboundDST processing 82 generates check slice requests 1-8 and sends, via thenetwork 24, the check slice requests 1-8 to the DST execution units 1-8.

FIG. 45B illustrates further steps of the example of the rebuilding ofthe data, where the inbound DST processing 82 receives, via the network24, a decode threshold number of encoded data slices in response from atleast some of the storage units, where the set of encoded data slicesinclude the total number of encoded data slices, and where the decodethreshold number is less than the total number. For example, DSTexecution units 1-6 issues read slice responses 1-6 to the inbound DSTprocessing 82, where each read slice response includes one or more of aslice name, an encoded data slice, and one or more revision numbers whenthe read slice response includes at least one encoded data slice. Forinstance, the DST execution unit 1 generates the read slice response 1to include encoded data slice 1, the DST execution unit 2 generates theread slice response 2 to include encoded data slice 2, the DST executionunit 4 generates the read slice response 4 to include encoded data slice4, the DST execution unit 5 generates the read slice response 5 toinclude encoded data slice 5, and the DST execution unit 6 generates theread slice response 6 to include encoded data slice 6. As such, theinbound DST processing 82 receives encoded data slices 1, 2, 4, 5, and 6as the decode threshold number of encoded data slices.

Having received the decode threshold number of encoded data slices fromthe read slice responses 1-6, inbound DST processing 82 receives aremaining number of slice status responses from one or more otherstorage units of the storage units regarding a remaining number ofencoded data slices, where the remaining number is equal or less than adifference between the total number and the decode threshold number. Theremaining number of slice status responses includes one or more ofanother read slice response and a status check response. As a specificexample, the inbound DST processing 82 receives three slice statusresponses as the remaining number of slice status responses when thetotal number is 8 and the decode threshold number is 5. For instance,DST execution unit 3 generates a read slice response 3 without encodeddata slice 3 when a storage error has occurred for encoded data slice 3(e.g., missing, corrupted). As another instance, DST execution unit 7generates a check slice response 7 that indicates a storage errorassociated with encoded data slice 7. As yet another instance, DSTexecution unit 8 generates a check slice response 8 that indicates thatencoded data slice 8 is stored with no storage errors.

Having received the decode threshold number of encoded data slices, theDS error decoding 182 decodes the decode threshold number of encodeddata slices to reproduce the data segment 526. For example, the DS errordecoding 182 decodes encoded data slices 1, 2, 4, 5, and 6 using thedispersed storage error coding function to reproduce the data segment526. Having received the remaining number of slice status responses, theerror detector 522 interprets the remaining number of slice statusresponses to determine whether one of the remaining number of encodeddata slices includes an error.

As a specific example of the interpreting of the remaining number ofslice status responses, the error detector 522 determines whether, forone of the read requests, an encoded data slice was not received withina given time period (e.g., 5 seconds). For instance, the error detector522 determines that the encoded data slice 3 was not received within thegiven time period. When the encoded data slice was not received in thegiven time period, the error detector 522 interprets the encoded dataslice not being received within the given time frame as the one of theremaining number of slices status responses indicating that the encodeddata slice includes the error. For instance, the error detector 522indicates that encoded data slice three includes the error.

As another specific example of the interpreting of the remaining numberof slice status responses, the error detector 522 determines whether,for one of the read requests, an encoded data slice was received withina given time period and includes a revision error. For instance, theerror detector 522 determines that the most recent revision of encodeddata slice 3 is missing. When the encoded data slice was received in thegiven time period and includes the revision error, the error detector522 interprets the encoded data slice as the one of the remaining numberof slices status responses indicating that the encoded data sliceincludes the error. For instance, the error detector 522 indicates thatthe encoded data slice 3 includes the error.

As yet another specific example of the interpreting of the remainingnumber of slice status responses, the error detector 522 determineswhether, for one of the read requests, an encoded data slice wasreceived within a given time period and includes a corruption error. Forinstance, the error detector 522 determines that the encoded data slice3 includes the corruption error when a comparison of a received encodeddata slice 3 compares unfavorably to a stored integrity information forthe encoded data slice 3. When the encoded data slice was received inthe given time period and includes the corruption error, the errordetector 522 interprets the encoded data slice as the one of theremaining number of slices status responses indicating that the encodeddata slice includes the error. For instance, the error detector 522indicates that the encoded data slice 3 includes the error.

Alternatively, error detector 522 receives at least some of theremaining number of slice status responses in response to the statuscheck requests. For example, the error detector 522 receives the checkslice response 7, where the check slice response 7 indicates that atleast one error has occurred (e.g., missing all revisions of encodeddata slice 7, missing a most recent revision of the encoded data slice7, encoded data slice 7 has failed and integrity test).

FIG. 45C illustrates further steps of the example of the rebuilding ofthe data, where the DS error decoding 182 outputs the reproduced datasegment 526 and provides the reproduced data segment 526 to the DS errorencoding 112. Having provided the reproduced data segment 526 to the DSerror encoding 112, the error detector 522 outputs slice identities ofthe encoded data slices associated with errors to the DS error encoding112. For example, the error detector 522 identifies encoded data slices3 and 7 as including the errors.

FIG. 45D illustrates final steps of the example of the rebuilding of thedata. When the one of the remaining number of encoded data slicesincludes the error, the DS error encoding 112 generate a rebuilt encodeddata slice based on the reproduced data segment to replace the one ofthe remaining number of encoded data slices that includes the error. Forexample, the DS error encoding 112 encodes the reproduced data segment526 using the dispersed storage error encoding function to reproduce theset of encoded data slices.

Having reproduced the set of encoded data slices, the DS error encoding112 identifies one or more of the reproduced encoded data slices basedon the identified encoded data slices that includes the errors. Forexample, the DS error encoding 112 identifies reproduced encoded dataslices 3 and 7 based on the identified encoded data slices 3 and 7 asincluding the errors. Having identified the one or more reproducedencoded data slices, the outbound DST processing 80 sends, via thenetwork 24, the identified reproduced encoded data slices to thecorresponding DST execution units of the DST execution unit set 520 forstorage. For example, the outbound DST processing 80 sends, via thenetwork 24, a write slice request 3 to the DST execution unit 3, wherethe write slice request 3 includes the reproduced encoded data slice 3and the outbound DST processing 80 sends, via the network 24, a writeslice request 7 to the DST execution unit 7, where the write slicerequest 7 includes the reproduced encoded data slice 7.

FIG. 45E is a flowchart illustrating an example of rebuilding data. Themethod begins at step 530 where a processing module of a dispersedstorage network (DSN) (e.g., of a distributed storage and task (DST)client module) sends representations of a read-rebuild inquiry requestto storage units of the DSN, where the storage units collectively storea set of encoded data slices and where a data segment was encoded inaccordance with a dispersed storage error coding function to produce theset of encoded data slices. The sending may include one or more ofinterpreting a test schedule, interpreting an error message, andprocessing a data segment read request to produce the read-rebuildinquiry request.

The sending further includes generating the representations of theread-rebuild inquiry request. As a specific example, the processingmodule generates read requests regarding a read threshold number ofencoded data slices of the set of encoded data slices, where the readthreshold number is less than the total number and equal to or greaterthan the decode threshold number. For instance, the processing modulegenerates 6 read requests when the read threshold is 6, the total numberis 8, and the decode number is 5.

As another specific example, the processing module generates statuscheck requests regarding a difference number of encoded data slices ofthe set of encoded data slices, where the difference number is equal orless than a difference between the total number and the read thresholdnumber. For instance, the processing module generates 2 status checkrequests when the difference number is 2 (e.g., 2=8-6).

Alternatively, or in addition to, after sending the representations ofthe read-rebuild inquiry request and when another data segment readrequest for the data segment is not received prior to expiration of astatus check time out period, the processing module sends status checkrequests regarding the set of encoded data slices. For instance, theprocessing module sends 8 status check requests regarding the set ofencoded data slices to the storage units.

The method continues at step 532 where the processing module receives adecode threshold number of encoded data slices in response from at leastsome of the storage units, where the set of encoded data slices includethe total number of encoded data slices, and where the decode thresholdnumber is less than the total number. For example, the processing modulereceives read responses that includes the decode threshold number (e.g.,5) of encoded data slices.

The method continues at step 534 where the processing module receives aremaining number of slice status responses from one or more otherstorage units of the storage units regarding a remaining number ofencoded data slices, where the remaining number is equal or less than adifference between the total number and the decode threshold number. Theprocessing module receives at least some of the remaining number ofslice status responses in response to the status check requests. As aspecific example, the processing module receives 3 slice statusresponses (e.g., 8−5=3), where the 3 slice status responses includes a6th read response and two status check responses. The method continuesat step 536 where the processing module decodes the decode thresholdnumber of encoded data slices to reproduce the data segment.

The method continues at step 538 where the processing module interpretsthe remaining number of slice status responses to determine whether oneof the remaining number of encoded data slices includes an error. As aspecific example, the processing module determines whether, for one ofthe read requests, an encoded data slice was not received within a giventime period. When the encoded data slice was not received in the giventime period, the processing module interprets the encoded data slice notbeing received within the given time frame as the one of the remainingnumber of slices status responses indicating that the encoded data sliceincludes the error.

As another specific example, the processing module determines whether,for one of the read requests, an encoded data slice was received withina given time period and includes a revision error. When the encoded dataslice was received in the given time period and includes the revisionerror, the processing module interprets the encoded data slice as theone of the remaining number of slices status responses indicating thatthe encoded data slice includes the error.

As yet another example, the processing module determines whether, forone of the read requests, an encoded data slice was received within agiven time period and includes a corruption error. When the encoded dataslice was received in the given time period and includes the corruptionerror, the processing module interprets the encoded data slice as theone of the remaining number of slices status responses indicating thatthe encoded data slice includes the error.

When the one of the remaining number of encoded data slices includes theerror, the method continues at step 540 where the processing modulegenerates a rebuilt encoded data slice based on the reproduced datasegment to replace the one of the remaining number of encoded dataslices that includes the error. For example, the processing moduledisperse storage error encodes the reproduced data segment to produce areproduced set of encoded data slices. Having produced the reproducedset of encoded data slices, the processing module identifies the rebuiltencoded data slice based on the one of the remaining number of encodeddata slices that includes the error.

FIG. 46A is a diagram of another embodiment of a dispersed storagenetwork (DSN) that includes a configuration module 542, a DSN memory544, and a DSN entity 546. The configuration module 542 and the DSNentity 546 may be implemented using one or more of a dispersed storage(DS) processing module, a DS processing unit, a dispersed storage andtask (DST) processing module, the DST processing unit 16 of FIG. 1, theuser device 12 of FIG. 1, a DS managing unit, the DSTN managing unit 18of FIG. 1, the DST execution unit 36 of FIG. 1, and a DS unit. The DSNmemory 544 includes a plurality of storage devices, where a storagedevice may be implemented using one or more of a memory device, a memoryarray, a storage unit, the DS unit, the DST execution unit 36 of FIG. 1,and the user device 12 of FIG. 1.

The system functions to provide an install package, including at leastone of software 548 (e.g., executable instructions for a processingmodule of the DSN entity 546) and configuration information (e.g.,memory mapping, memory allocation, port mapping, device type, identityinformation, security information, registration information, whichportions of the software to execute, a DSN address range, access controllist information, permissions information, etc.), and to utilize theinstall package. The configuration module 542 performs a series of stepsto provide the install package. The configuration module 542 determinesto provide the install package based on at least one of interpreting aschedule, detecting that the DSN entity 546 is in need of the installpackage, detecting that the DSN entity 546 has been replaced, receivinga request, detecting a software failure associated with the DSN entity546, detecting a configuration failure associated with the DSN entity546, and receiving an error message. For example, the DSN entity 546 isinstalled and sends a message to the configuration module indicatingthat the DSN entity 546 is available for assignment within the DSN.

The configuration module 542 identifies the DSN entity 546 by at leastone of initiating a query, interpreting an error message, and receivingan identifier of the DSN, where the identifier includes at least one ofan Internet protocol (IP) address, a universal unique identifier (UUID),and any other identifier. The configuration module 542 generates theconfiguration information for the DSN entity 546 based on one or more ofan entity type of the DSN entity 546 and one or more vault assignmentsfor the DSN entity 546. For example, the configuration module 542accesses registry information associated with a vault assigned to theDSN entity 546 to retrieve at least a portion of the configurationinformation. The configuration module 542 obtains the software 548 forthe DSN entity 546. The obtaining includes at least one of initiating aquery to a software server, receiving the software 548 from the softwareserver, accessing a manufacturer software distribution portal, andauto-generating the software 548 based on requirements listed withinregistry information of the DSN.

The configuration module 542 generates the install package to includethe configuration information and the software 548. The configurationmodule 542 encodes the install package using a dispersed storage errorcoding function to produce a plurality of sets of install package slices550. The configuration module 542 sends the plurality of sets of installpackage slices 550 to the DSN memory 544 for storage. The configurationmodule 542 updates at least one of a dispersed hierarchical index and aDSN directory to associate the identifier of the DSN entity and a DSNaddress utilized to store the plurality of sets of install packageslices in the DSN memory. The updating of the dispersed hierarchicalindex includes generating a new entry (e.g., that includes theidentifier the DSN entity and the DSN address) for the dispersedhierarchical index, encoding the new entry using the dispersed storageerror coding function to produce a set of install index slices 552, andsending the set of install index slices 552 to the DSN memory 544 forstorage.

The DSN entity 546 performs a series of steps to utilize the installpackage. The DSN entity 546 determines that at least one of theconfiguration information and the software 548 is required (e.g.,detecting an error, receiving a new assignment message, receiving areconfiguration request, receiving notification that a new version ofsoftware is available, etc.). The DSN entity 546 accesses the at leastone of the dispersed hierarchical index and the DSN directory toidentify the DSN address associated with the install package. Theaccessing of the dispersed hierarchical index includes generating anindex key associated with the identifier of the DSN entity, issuingindex slice requests 554 to the DSN memory 544 based on the index keyand receiving install index slices 556 to search the dispersedhierarchical index for an index node that includes the entry associatedwith the DSN entity, decoding the install index slices 552 to reproducea recovered index node that includes the entry, and extracting the DSNaddress associated with the install package from the entry of therecovered index node.

The DSN entity 546 issues one or more sets of install package slicerequests 558 using the DSN address associated with the install packageto the DSN memory. The DSN entity 546 receives install package sliceresponses 560 from the DSN memory 544 that includes at least a decodethreshold number of install package slices for each set of installpackage slices of the plurality of sets of install package slices. Foreach set of install package slices, the DSN entity 546 decodes the atleast the decode threshold number of install package slices to reproduceat least a portion of the install package. The DSN entity 546 extractsthe at least one of the configuration information and the software 548from the reproduced install package. The DSN entity 546 utilizes the atleast one of the configuration information and the software 548. Forexample, the DSN entity installs the software 548 within memory of theDSN entity, writes the configuration information to memory of the DSNentity, and activates the software 548.

FIG. 46B is a flowchart illustrating an example of updatingconfiguration information and software. A method to perform a series ofsteps to store and utilize an install package begins with step 562 wherea configuration module (e.g., a dispersed storage (DS) managing unit)determines to provide the install package for a dispersed storagenetwork (DSN) entity (e.g., a DS processing unit). The method continuesat 564 where the configuration module identifies the DSN entity. Theidentifying includes at least one of obtaining an identifier of the DSNentity and identifying a DSN entity type. The method continues at step566 where the configuration module generates configuration informationfor the DSN entity. The generating includes at least one of performing alookup, retrieving, accessing registry information based on one or moreof the identifier the DSN entity and the DSN entity type, anddetermining based on a configuration algorithm. The method continues atstep 568 where the configuration module obtains software for the DSNentity. The obtaining includes at least one of initiating a request,receiving, and retrieving.

The method continues at step 570 where the configuration modulegenerates the install package to include one or more of theconfiguration information, the software, the identifier of the DSNentity, an identifier of the configuration module, a timestamp, arevision indicator, integrity information, and the DSN entity type. Themethod continues at step 572 where the configuration module encodes theinstall package using a dispersed storage error coding function toproduce a plurality of sets of install package slices. The methodcontinues at step 574 where the configuration module stores theplurality of sets of install package slices in a DSN. For example, theconfiguration module generates a DSN address associated with the installpackage, generates a plurality of sets of slice names based on the DSNaddress, generates one or more sets of write slice requests thatincludes the plurality of sets of slice names and the plurality of setsof install package slices, and outputs the one or more sets of writeslice requests to the DSN.

The method continues at step 576 where the configuration module updatesa dispersed hierarchical index to associate the identifier the DSNentity and the DSN address. The updating includes generating an entrythat includes the identifier the DSN entity and the DSN address,recovering an index node of the dispersed hierarchical index based onthe identifier of the DSN entity, modifying the recovered index node toinclude the entry to produce a modified index node, encoding themodified index node using the dispersed storage error coding function toproduce a set of updated index node slices, and issuing a set of writeslice request to the DSN where the set of write slice requests includesthe updating the set of index node slices.

The method continues to perform more steps associated with using theinstall package and begins with step 578 where the DSN entity determinesthat at least one of current configuration information of the DSN entityand current software of the DSN entity requires updating. Thedetermining includes at least one of detecting an error, receiving amessage with regards to an update, receiving and indicator for a newconfiguration assignment, receiving an error message. The methodcontinues at step 580 where the DSN entity accesses at least one of thedispersed hierarchical index and a DSN directory to identify the DSNaddress associated with the install package for the DSN entity. Themethod continues at step 582 where the DSN entity issues install packageslice requests using the DSN address to the DSN. The method continues atstep 584 where they DSN entity receives install package slice responses.

The method continues at step 586 where the DSN entity decodes theinstall package slices using the dispersed storage error coding functionto reproduce the install package. The method continues at step 588 wherethe DSN entity extracts at least one of the configuration informationand the software from the install package. The DSN entity may select aportion of the at least one of the configuration information and thesoftware based on the determining that the at least one of the currentconfiguration information and the current software requires updating.The method continues at step 590 where the DSN entity activates the atleast one of the configuration information and the software within theDSN entity. For example, the DSN entity installs the software, installsthe configuration information, and reboots to use the install package.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “operably coupled to”, “coupled to”, and/or “coupling” includesdirect coupling between items and/or indirect coupling between items viaan intervening item (e.g., an item includes, but is not limited to, acomponent, an element, a circuit, and/or a module) where, for indirectcoupling, the intervening item does not modify the information of asignal but may adjust its current level, voltage level, and/or powerlevel. As may further be used herein, inferred coupling (i.e., where oneelement is coupled to another element by inference) includes direct andindirect coupling between two items in the same manner as “coupled to”.As may even further be used herein, the term “operable to” or “operablycoupled to” indicates that an item includes one or more of powerconnections, input(s), output(s), etc., to perform, when activated, oneor more its corresponding functions and may further include inferredcoupling to one or more other items. As may still further be usedherein, the term “associated with”, includes direct and/or indirectcoupling of separate items and/or one item being embedded within anotheritem. As may be used herein, the term “compares favorably”, indicatesthat a comparison between two or more items, signals, etc., provides adesired relationship. For example, when the desired relationship is thatsignal 1 has a greater magnitude than signal 2, a favorable comparisonmay be achieved when the magnitude of signal 1 is greater than that ofsignal 2 or when the magnitude of signal 2 is less than that of signal1.

As may also be used herein, the terms “processing module”, “processingcircuit”, and/or “processing unit” may be a single processing device ora plurality of processing devices. Such a processing device may be amicroprocessor, micro-controller, digital signal processor,microcomputer, central processing unit, field programmable gate array,programmable logic device, state machine, logic circuitry, analogcircuitry, digital circuitry, and/or any device that manipulates signals(analog and/or digital) based on hard coding of the circuitry and/oroperational instructions. The processing module, module, processingcircuit, and/or processing unit may be, or further include, memoryand/or an integrated memory element, which may be a single memorydevice, a plurality of memory devices, and/or embedded circuitry ofanother processing module, module, processing circuit, and/or processingunit. Such a memory device may be a read-only memory, random accessmemory, volatile memory, non-volatile memory, static memory, dynamicmemory, flash memory, cache memory, and/or any device that storesdigital information. Note that if the processing module, module,processing circuit, and/or processing unit includes more than oneprocessing device, the processing devices may be centrally located(e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that if the processing module, module, processing circuit,and/or processing unit implements one or more of its functions via astate machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory and/or memory element storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry. Still further note that, the memoryelement may store, and the processing module, module, processingcircuit, and/or processing unit executes, hard coded and/or operationalinstructions corresponding to at least some of the steps and/orfunctions illustrated in one or more of the Figures. Such a memorydevice or memory element can be included in an article of manufacture.

The present invention has been described above with the aid of methodsteps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention. Further, theboundaries of these functional building blocks have been arbitrarilydefined for convenience of description. Alternate boundaries could bedefined as long as the certain significant functions are appropriatelyperformed. Similarly, flow diagram blocks may also have been arbitrarilydefined herein to illustrate certain significant functionality. To theextent used, the flow diagram block boundaries and sequence could havebeen defined otherwise and still perform the certain significantfunctionality. Such alternate definitions of both functional buildingblocks and flow diagram blocks and sequences are thus within the scopeand spirit of the claimed invention. One of average skill in the artwill also recognize that the functional building blocks, and otherillustrative blocks, modules and components herein, can be implementedas illustrated or by discrete components, application specificintegrated circuits, processors executing appropriate software and thelike or any combination thereof.

The present invention may have also been described, at least in part, interms of one or more embodiments. An embodiment of the present inventionis used herein to illustrate the present invention, an aspect thereof, afeature thereof, a concept thereof, and/or an example thereof. Aphysical embodiment of an apparatus, an article of manufacture, amachine, and/or of a process that embodies the present invention mayinclude one or more of the aspects, features, concepts, examples, etc.described with reference to one or more of the embodiments discussedherein. Further, from figure to figure, the embodiments may incorporatethe same or similarly named functions, steps, modules, etc. that may usethe same or different reference numbers and, as such, the functions,steps, modules, etc. may be the same or similar functions, steps,modules, etc. or different ones.

While the transistors in the above described figure(s) is/are shown asfield effect transistors (FETs), as one of ordinary skill in the artwill appreciate, the transistors may be implemented using any type oftransistor structure including, but not limited to, bipolar, metal oxidesemiconductor field effect transistors (MOSFET), N-well transistors,P-well transistors, enhancement mode, depletion mode, and zero voltagethreshold (VT) transistors.

Unless specifically stated to the contra, signals to, from, and/orbetween elements in a figure of any of the figures presented herein maybe analog or digital, continuous time or discrete time, and single-endedor differential. For instance, if a signal path is shown as asingle-ended path, it also represents a differential signal path.Similarly, if a signal path is shown as a differential path, it alsorepresents a single-ended signal path. While one or more particulararchitectures are described herein, other architectures can likewise beimplemented that use one or more data buses not expressly shown, directconnectivity between elements, and/or indirect coupling between otherelements as recognized by one of average skill in the art.

The term “module” is used in the description of the various embodimentsof the present invention. A module includes a processing module, afunctional block, hardware, and/or software stored on memory forperforming one or more functions as may be described herein. Note that,if the module is implemented via hardware, the hardware may operateindependently and/or in conjunction software and/or firmware. As usedherein, a module may contain one or more sub-modules, each of which maybe one or more modules.

While particular combinations of various functions and features of thepresent invention have been expressly described herein, othercombinations of these features and functions are likewise possible. Thepresent invention is not limited by the particular examples disclosedherein and expressly incorporates these other combinations.

What is claimed is:
 1. A method for execution by one or more computingdevices of a storage network, the method comprises: executing a readoperation to reconstruct data from a decode threshold number of encodeddata slices of a set of encoded data slices that is stored in storageunits of the storage network, wherein the data was encoded in accordancewith an error coding function to produce the set of encoded data slices;during the executing the read operation: determining an encoded dataslice not within the decode threshold number of encoded data slices hasan integrity check value that does not substantially match a knownintegrity check value for the encoded data slice; and rebuilding theencoded data slice based on the decode threshold number of encoded dataslices.
 2. The method of claim 1 further comprises: determining arevision error for a second encoded data slice of the set of encodeddata slices; and rebuilding the second encoded data slice based on thedecode threshold number of encoded data slices.
 3. The method of claim 1further comprises: determining an expected read response to a readrequest associated with a second encoded data slice of the set ofencoded data slices was not received; and rebuilding the second encodeddata slice based on the decode threshold number of encoded data slices.4. The method of claim 1 further comprises: determining a second encodeddata slice of the set of encoded data slices is corrupted; andrebuilding the second encoded data slice based on the decode thresholdnumber of encoded data slices.
 5. The method of claim 1 furthercomprises: determining a second encoded data slice of the set of encodeddata slices is flagged in a rebuilding list; and rebuilding the secondencoded data slice based on the decode threshold number of encoded dataslices.
 6. The method of claim 1 further comprises: determining a secondencoded data slice of the set of encoded data slices as being previouslyidentified during a rebuilding process; and rebuilding the secondencoded data slice based on the decode threshold number of encoded dataslices.
 7. The method of claim 1 further comprises: error decoding atleast the decode threshold number of encoded data slices to produce thereconstructed data; and determining to temporarily keep thereconstructed data until an expiration of a time period.
 8. The methodof claim 7 further comprises: receiving a read request for the set ofencoded data slices; and determining to use the reconstructed data inexecuting the read request.
 9. The method of claim 1, wherein the set ofencoded data slices includes a total width number, and wherein thedecode threshold number is less than the total width number.
 10. Acomputing device of a storage network comprises: an interface; memory;and a processing module operably coupled to the memory and theinterface, wherein the processing module is operable to: execute a readoperation to reconstruct data from a decode threshold number of encodeddata slices of a set of encoded data slices that is stored in storageunits of the storage network, wherein the data was encoded in accordancewith an error coding function to produce the set of encoded data slices;during the executing the read operation: determine an encoded data slicenot within the decode threshold number of encoded data slices has anintegrity check value that does not substantially match a knownintegrity check value for the encoded data slice; and rebuild theencoded data slice based on the decode threshold number of encoded dataslices.
 11. The computing device of claim 10, wherein the processingmodule is further operable to: determine a revision error for a secondencoded data slice of the set of encoded data slices; and rebuild thesecond encoded data slice based on the decode threshold number ofencoded data slices.
 12. The computing device of claim 10, wherein theprocessing module is further operable to: determine an expected readresponse to a read request associated with a second encoded data sliceof the set of encoded data slices was not received; and rebuild thesecond encoded data slice based on the decode threshold number ofencoded data slices.
 13. The computing device of claim 10, wherein theprocessing module is further operable to: determine a second encodeddata slice of the set of encoded data slices is corrupted; and rebuildthe second encoded data slice based on the decode threshold number ofencoded data slices.
 14. The computing device of claim 10, wherein theprocessing module is further operable to: determine a second encodeddata slice of the set of encoded data slices is flagged in a rebuildinglist; and rebuild the second encoded data slice based on the decodethreshold number of encoded data slices.
 15. The computing device ofclaim 10, wherein the processing module is further operable to:determine a second encoded data slice of the set of encoded data slicesas being previously identified during a rebuilding process; and rebuildthe second encoded data slice based on the decode threshold number ofencoded data slices.
 16. The computing device of claim 10, wherein theprocessing module is further operable to: error decode at least thedecode threshold number of encoded data slices to produce thereconstructed data; and determine to temporarily keep the reconstructeddata until an expiration of a time period.
 17. The computing device ofclaim 16, wherein the processing module is further operable to: receivea read request for the set of encoded data slices; and determine to usethe reconstructed data in executing the read request.
 18. The computingdevice of claim 10, wherein the set of encoded data slices includes atotal width number, and wherein the decode threshold number is less thanthe total width number.